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The article summarizes the Proceedings of the International Ambulatory Drug Safety Symposium held in Munich, Germany in June 2023. The symposium aimed to address challenges in maximizing ambulatory drug safety and brought together scientists from 12 countries. The symposium focused on knowledge generation and implementation, including innovations in research, risk prediction, surveillance, decision support, collaboration, and intervention design. The symposium discussed the challenges of improving medication safety in ambulatory care and emphasized the need for tailored interventions and alignment between knowledge generation and implementation efforts. Experts in pharmacoepidemiology, health services research, and clinical medicine participated in the symposium. [Extracted from the article]

Introduction: COVID-19 vaccines were rapidly authorised, thus requiring intense post-marketing re-evaluation of their benefit-risk profile. A multi-national European collaboration was established with the aim to prospectively monitor safety of the COVID-19 vaccines through web-based survey of vaccinees. Methods: A prospective cohort event monitoring study was conducted with primary consented data collection in seven European countries. Through the web applications, participants received and completed baseline and up to six follow-up questionnaires on self-reported adverse reactions for at least 6 months following the first dose of COVID-19 vaccine (Netherlands, France, Belgium, UK, Italy) and baseline and up to ten follow-up questionnaires for one year in Germany and Croatia. Rates of adverse reactions have been described by type (solicited, non-solicited; serious/non-serious; and adverse events of special interest) and stratified by vaccine brand. We calculated the frequency of adverse reaction after dose 1 and prior to dose 2 among all vaccinees who completed at least one follow-up questionnaire. Results: Overall, 117,791 participants were included and completed the first questionnaire in addition to the baseline: 88,196 (74.9%) from Germany, 27,588 (23.4%) from Netherlands, 984 (0.8%) from France, 570 (0.5%) from Italy, 326 (0.3%) from Croatia, 89 (0.1%) from the UK and 38 (0.03%) from Belgium. There were 89,377 (75.9%) respondents who had received AstraZeneca vaccines, 14,658 (12.4%) BioNTech/Pfizer, 11,266 (9.6%) Moderna and 2490 (2.1%) Janssen vaccines as a first dose. Median age category was 40–49 years for all vaccines except for Pfizer where median age was 70–79 years. Most vaccinees were female with a female-to-male ratio of 1.34, 1.96 and 2.50 for AstraZeneca, Moderna and Janssen, respectively. BioNtech/Pfizer had slightly more men with a ratio of 0.82. Fatigue and headache were the most commonly reported solicited systemic adverse reactions and injection-site pain was the most common solicited local reaction. The rates of adverse events of special interest (AESIs) were 0.1–0.2% across all vaccine brands. Conclusion: This large-scale prospective study of COVID-19 vaccine recipients showed, for all the studied vaccines, a high frequency of systemic reactions, related to the immunogenic response, and local reactions at the injection site, while serious reactions or AESIs were uncommon, consistent with those reported on product labels. This study demonstrated the feasibility of setting up and conducting cohort event monitoring across multiple European countries to collect safety data on novel vaccines that are rolled out at scale in populations which may not have been included in pivotal trials. [ABSTRACT FROM AUTHOR]

Introduction: Thrombotic thrombocytopenia syndrome (TTS) events were reported very rarely following the coronavirus disease 2019 (COVID-19) vaccine AstraZeneca (Vaxzevria). Clinical and demographic characteristics of the affected people, including the outcomes of TTS events, need to be examined using available information to better understand aspects of this association.Objective: To analyse clinical and demographic information of TTS events, including calculating the case fatality of reported cases of TTS by age and sex, using spontaneously reported data from the UK's Yellow Card spontaneous reporting system of suspected adverse drug reactions.Methods: TTS events reported to the Yellow Card scheme were extracted at weekly time points between 12 May 2021 and 25 May 2022. Cumulative numbers of TTS cases and deaths were recorded for each weekly interval, overall and stratified by age, sex, and vaccine dose.Results: To 25 May 2022, 443 cases (81 fatal, 18.28%) had been reported in the UK. Events more frequently occurred following the first vaccine dose. No trends were observed for case fatality overall, or by age or sex.Conclusion: In the UK, case fatality of TTS events reported to the Medicines and Health products Regulatory Agency (MHRA) following Vaxzevria has been approximately 17-18% since May 2021. There were no statistical differences in fatality based on age or sex. Most reports followed the first vaccine dose; none have been reported following a third dose to date, although Vaxzervia was not recommended for a third dose of COVID-19 vaccine in the UK. TTS remains very rare, and benefits of vaccination outweigh the risks. [ABSTRACT FROM AUTHOR]

In pharmacoepidemiology, comparison studies can provide a useful estimate of the level of increased or decreased risk of specific events with a medication (through a measure of effect). A key focus of pharmacoepidemiological studies is the safety and effectiveness of medicines in their real-world use, and adequate comparisons of effect estimates are critical. However, consideration of guidelines, pharmacoeconomic assessments, and policies for reimbursement have made comparisons in pharmacoepidemiological studies far more difficult to conduct in recent years. Where certain subject characteristics influence the probability of being exposed to a treatment, this can introduce issues of selection bias and confounding. Methodologies are available to minimise selection bias (through case-only and randomised study designs) and deal with confounding (such as regression modelling or propensity score matching methods), however these each have their own limitations. Where prescribing guidelines are present, conducting comparisons in pharmacoepidemiology produces many challenges and not all of these can be easily overcome. Patient channelling can be more frequent with adherence to clinical guidelines compared with when prescribing decisions by doctors are based predominantly on their clinical judgement. Use of a contextual cohort could be considered as an option to characterise the adoption of new medications into clinical practice and describe the prevalence of clinical characteristics and risk factors in the two cohorts, rather than compare event rates and produce an estimate of effect. [ABSTRACT FROM AUTHOR]

The article offers guidelines on how to evaluate serious adverse events conducted during the trial of a vaccine to prevent the transmission of COVID-19. Topics mentioned include the criteria for causality assessment, the algorithm used by the World Health Organization (WHO) for causality assessment, and the importance of validating the diagnosis before causality assessment.

Introduction and Objective: COVID-19 is an ongoing, global public health crisis for which safe and effective treatments need to be identified. The benefit-risk balance for the use of lopinavir-ritonavir in COVID-19 needs to be monitored on an ongoing basis, therefore a systematic benefit-risk assessment was designed and conducted. A key objective of this study was to provide a platform for a dynamic systematic benefit-risk evaluation; although initially this evaluation is likely to contain limited information, it is required because of the urgent unmet public need. Importantly, it allows additional data to be incorporated as they become available, and re-evaluation of the benefit-risk profile. Methods: A systematic benefit-risk assessment was conducted using the Benefit-Risk Action Team (BRAT) framework. The exposure of interest was lopinavir-ritonavir treatment in severe COVID-19 compared to standard of care, placebo or other treatments. A literature search was conducted in PubMed and Embase to identify peer-reviewed papers reporting clinical outcomes. Two clinicians constructed a value tree and ranked key benefits and risks in order of considered clinical importance. Results: We screened 143 papers from PubMed and 264 papers from Embase for lopinavir-ritonavir; seven papers were included in the final benefit-risk assessment. In comparison to standard of care, data for several key benefits and risks were identified for lopinavir-ritonavir. Time to clinical improvement was not significantly different for lopinavir-ritonavir in comparison to standard of care (hazard ratio 1.31, 95% confidence interval 0.95–1.80). From one study, there were fewer cases of acute respiratory distress syndrome with lopinavir-ritonavir compared with standard of care (13% vs 27%). There also appeared to be fewer serious adverse events with lopinavir-ritonavir (20%) vs standard of care (32%). Limited data were available for comparison of lopinavir-ritonavir to other treatments. Conclusions: Based on currently available data, there was no clear benefit for the use of lopinavir-ritonavir compared to standard of care in severe COVID-19. Risk data suggested a possible decrease in serious adverse events. There was a reduction in acute respiratory distress syndrome with lopinavir-ritonavir in one study. Overall, the benefit-risk profile for lopinavir-ritonavir in severe COVID-19 cannot be considered positive until further efficacy and effectiveness data become available. [ABSTRACT FROM AUTHOR]

Introduction: There is a need to identify effective, safe treatments for COVID-19 (coronavirus disease) rapidly, given the current, ongoing pandemic. A systematic benefit-risk assessment was designed and conducted to examine the benefit-risk profile of remdesivir in COVID-19 patients compared with standard of care, placebo or other treatments. A key objective of this study was to provide a platform for a dynamic systematic benefit-risk evaluation, which starts with inevitably limited information (to meet the urgent unmet public health need worldwide), then update the benefit-risk evaluation as more data become available.Methods: The Benefit-Risk Action Team (BRAT) framework was used to assess the overall benefit-risk of the use of remdesivir as a treatment for COVID-19 compared with standard of care, placebo or other treatments. We searched PubMed, Google Scholar and government agency websites to identify literature reporting clinical outcomes in patients taking remdesivir for COVID-19. A value tree was constructed and key benefits and risks were ranked by two clinicians in order of considered importance.Results: Using the BRAT method, several key benefits and risks for use of remdesivir in COVID-19 compared with placebo have been identified. In one trial, the benefit of time to clinical improvement was not statistically significant (21 vs 23 days, HR 1.23, 95% CI 0.87-1.75), although the study was underpowered. In another trial, a shorter time to recovery in patients treated with remdesivir was observed (11 vs 15 days), with non-significant reduced mortality risk (8% vs 12%). Risk data were only available from one trial. This trial reported fewer serious adverse events in patients taking remdesivir (18%) compared with the placebo group (26%); however, more patients in the remdesivir group discontinued treatment as a result of an adverse event compared with those patients receiving placebo (12% vs 5%).Conclusions: Preliminary clinical trial results suggest that there may be a favourable benefit-risk profile for remdesivir compared with placebo in severe COVID-19 infection and further data on benefits would strengthen this evaluation. There is limited safety data for remdesivir, which should be obtained in further studies. The current framework summarises the key anticipated benefits and risks for which further data are needed. Ongoing clinical trial data can be incorporated into the framework when available to provide an updated benefit-risk assessment. [ABSTRACT FROM AUTHOR]

Introduction: Due to the complexity of biologics and the inherent challenges for manufacturing, it is important to know the specific brand name and batch number of suspected biologics in adverse drug reaction (ADR) reports. Objective: The aim of this study was to assess the extent to which biologics are traceable by brand name and batch number in UK hospital practice and in ADRs reported by patients and healthcare professionals. Methods: We performed an online hospital pharmacist survey to capture information on how specific product details are recorded during the processes of prescribing, dispensing and administration of biologics in routine UK hospital practice. We also assessed the proportion of ADR reports specifying brand name and batch number from electronic ADR reports submitted to the UK national spontaneous reporting database, the Yellow Card Scheme, between 1 January 2009 and 30 September 2017. Results: Brand name recording in routine hospital processes ranged from 79 to 91%, whereas batch numbers were less routinely recorded, ranging from 38 to 58%. Paper-based recording of product details was more commonly used for recording information. A total of 6108 electronic ADR reports were submitted to the Yellow Card Scheme for recombinant biologics, of which 38% and 15%, respectively, had an identifiable brand name and batch numbers. Whereas batch number traceability in electronic ADR reports improved slightly after the implementation of the European Union pharmacovigilance legislation in 2012, no improvement of brand name traceability was observed. Conclusion: Brand name and batch number traceability for biologics in UK ADR reports are generally low. Shortcomings in the systematic recording of product details in UK clinical practice may contribute to the limited traceability. [ABSTRACT FROM AUTHOR]

Introduction: Clinical trials have identified peripheral oedema (PO) as an adverse event of vildagliptin (an oral anti-diabetic drug [OAD]). A post-marketing study (PMS) was conducted to advance the understanding of vildagliptin use and particular safety concerns identified within the risk-management plan. PMS objectives included comparing the hazards between vildagliptin monotherapy and combination therapy for selected a priori identified risks, including PO.Aim: This study was a per-protocol supplementary analysis to investigate the pattern of onset and effect of vildagliptin combination therapy on PO risk.Methods: The PMS used an observational cohort design. OAD exposure, selected risk factors and outcome data were collected from general practitioners in England regarding vildagliptin users for the 6-month period after starting treatment. Data analysis comprised univariate case/non-case analysis, time-to-onset analysis and Cox proportional hazard models to estimate hazard ratios (HR) of PO adjusting for selected patients' baseline characteristics.Results: The study cohort included 4828 patients (median age 63 years; interquartile range [IQR] 54-71), 2692 of whom were male (55.8 %). The crude cumulative hazard of PO was 19.09 cases (95 % confidence interval [CI] 13.54-26.10) per 1000 person-years; 50 % of cases occurred during the first 34 days of treatment. A significantly faster time to PO onset was observed in patients prescribed concomitant sulfonylureas versus other treatment combinations (log rank test [LRT] p = 0.0365); in patients with a prior history of PO (LRT p < 0.001), arrhythmia (LRT p = 0.0003) or hypertension (LRT p = 0.0125); and in patients aged ≥60 years (LRT p = 0.0047). Similarly, the case/non-case univariate analysis indicated that patients with PO were older; had a higher prevalence of a history of either arrhythmia, hypertension or PO; and frequently used a sulfonylurea in combination. In the hazard function analysis, only sex and prior PO history had a profound effect on risk of PO after starting vildagliptin. Furthermore, effect modification was observed between sex and prior PO history; in male patients of average age (62 years), the HR was 12.84 (95 % CI 4.96-33.23); in females, it was 1.44 (95 % CI 0.32-6.40).Conclusions: In this planned supplementary analysis, the findings suggest that PO occurred most frequently within 1 month after starting treatment with vildagliptin, and previous PO history and male sex in elderly patients were important predictors of this risk. The observation that concomitant use of a sulfonylurea may also increase PO risk early after starting treatment should be taken into consideration if prescribing OADs in combination with vildagliptin. [ABSTRACT FROM AUTHOR]

The article discusses the Big Data for Pharmacovigilance conference held in June 2018. Topics mentioned include the improvement of pharmacovigilance through big data from electronic health records (EHR), the spontaneous reporting system (SRS) for identification of drug adverse events (AE), and the function of primary data collection in randomized clinical trials (RCTs) or SRS that cannot be replaced by real-world data (RWD).

Introduction: Deferasirox (EXJADE®, Novartis, UK) is an oral iron-chelating agent primarily used to reduce chronic iron overload in patients receiving blood transfusions for various chronic anaemias and some non-transfusion dependant anaemias.Objective: The aim of this study was to examine the utilisation and safety of deferasirox used in general practice in England.Method: A single exposure observational cohort study design was used. Patients were identified from dispensed prescriptions for deferasirox between September 2006 and September 2014. Outcome data were collected via postal questionnaires sent to prescribers ≥ 6 months after first dispensed prescription for an individual patient. Summary descriptive statistics were calculated.Results: The evaluable cohort consisted of 122 patients, of which 41.8% were aged 2-17 years. Frequent reasons for prescribing were sickle cell anaemia (27/103 where specified, 26.2%) and beta thalassaemia (26, 25.2%). The majority of patients (43/51, 84.3%) were prescribed the licensed doses of 10 or 20 mg/kg/day at start. Prior measurements of serum creatinine were only reported for a small proportion this study (18/122, 14.8%). In total, 91 incident events were reported, including two of raised serum creatinine.Conclusion: These results show that deferasirox is largely being prescribed for its licensed indications in general practice in England and events reported were consistent with the known safety profile. [ABSTRACT FROM AUTHOR]

The article offers information on the ninth Biennial Conference on Signal Detection and Interpretation in Pharmacovigilance held in June 2017. Topics discussed include importance of signal detection in pharmacovigilance in the age of big data, signals detection from social media, and computerized models supporting efficient decision making in signal management.

Background: Vaginal candidiasis is a common infection in women. The microflora of the vagina are influenced by a number of factors, including pregnancy, oral contraceptive use, menses and diabetes mellitus. Previous antibiotic use is generally accepted to be a risk factor for vaginal candidiasis but the published evidence to support this is limited.Aim: To determine the relative risk of vaginal candidiasis following the use of antibiotics compared with antidepressants in prescription-event monitoring (PEM) studies.Methods: Using data from postmarketing surveillance studies of six antibiotics and six antidepressants, conducted using the observational cohort technique of PEM, the number of reports of vaginal candidiasis was determined in women aged > or =16 years, in each of the first 7 weeks following a prescription for one of these drugs. The relative risks for vaginal candidiasis following the use of these antibiotics and for each of the individual antibiotics compared with antidepressants were calculated for each week and for the overall 7-week period. Women treated with antidepressants were the most suitable comparator group from the PEM database, as they were of a similar age range and the studies were conducted at a similar time period to those of the antibiotics. Also, there was no pharmacological plausibility for vaginal candidiasis being associated with antidepressants.Results: There were 188 reports of vaginal candidiasis in 31 588 women, aged > or =16 years, treated with antibiotics and 70 in the 45 492 treated with antidepressants. The relative risk for vaginal candidiasis (antibiotic/antidepressants), was highest in the second week, 10.70 (95% CI 4.86-23.55) but was also significantly greater in the first and third weeks after the start of treatment. The risk was also higher in each of the 3 weeks after starting the course for five of the antibiotics, compared individually to the group treated with antidepressants, the exception being fosfomycin, which had a much smaller cohort.Conclusion: This study shows a significant increase in the risk of developing vaginal candidiasis following the use of the antibiotics studied (ciprofloxacin, ofloxacin, norfloxacin, cefixime, azithromycin and fosfomycin) compared with that after taking the antidepressants fluvoxamine, fluoxetine, paroxetine, sertraline, venlafaxine and nefazodine in these PEM studies. [ABSTRACT FROM AUTHOR]

Introduction: Fluenz Tetra is an intranasal quadrivalent live attenuated influenza vaccine (QLAIV) and is recommended as the vaccine of choice for children in the 2014/2015 influenza season vaccination programme in the UK.Objective: The primary objective of the study was to estimate the crude incidence rate of adverse events of interest (AEIs) following vaccination with the nasal QLAIV early in the 2014/2015 influenza season in children and adolescents in England.Methods: A pilot non-interventional cohort post-authorisation safety study (PASS) was conducted during the 2014/2015 influenza season in England. Vaccinees were recruited via the mass vaccination programme in England. Participant outcomes, validated by a healthcare professional (general practitioner) where appropriate, were captured through questionnaires (surface mail, telephone, e-questionnaire). Data analysis comprised descriptive statistics and calculation of event risks and incidence rates, stratified by age group and selected co-morbidities.Results: The final evaluable cohort consisted of 385 participants; the median (interquartile range) age was 4 (3-9) years with a range of 2-17 years, and 53.2 % were female. The most frequently reported AEI was nasal congestion (n = 167; 43.4 %; 312.3 per 1000 patient-weeks [95 % CI 267.3-364.8]). Further frequently reported AEIs were malaise (n = 87; 22.6 %; 123.4 per 1000 patient-weeks [95 % CI 98.9-154.1]) and cough (n = 80; 20.8 %; 118.5 per 1000 patient-weeks [95 % CI 95.1-147.8]). Five hypersensitivity-type reactions were reported, although on follow-up none were true hypersensitivity reactions or required hospitalisation. No serious adverse events (SAEs) were reported, with no hospitalisations or deaths. No significant change in reactogenicity or other apparent safety signals was detected as part of this study.Conclusion: The pilot study showed no significant change in reactogenicity or other apparent safety signals from the data collected. Continued enhanced surveillance of seasonal influenza vaccines will ensure their ongoing safety for the prevention of serious illness from seasonal influenza outbreaks. [ABSTRACT FROM AUTHOR]

The evolving regulatory landscape has heightened the need for innovative, proactive, efficient and more meaningful solutions for 'real-world' post-authorization safety studies (PASS) that not only align with risk management objectives to gather additional safety monitoring information or assess a pattern of drug utilization, but also satisfy key regulatory requirements for marketing authorization holder risk management planning and execution needs. There is a need for data capture across the primary care and secondary care interface, or for exploring use of new medicines in secondary care to support conducting PASS. To fulfil this need, event monitoring has evolved. The Specialist Cohort Event Monitoring (SCEM) study is a new application that enables a cohort of patients prescribed a medicine in the hospital and secondary care settings to be monitored. The method also permits the inclusion of a comparator cohort of patients receiving standard care, or another counterfactual comparator group, to be monitored concurrently, depending on the study question. The approach has been developed in parallel with the new legislative requirement for pharmaceutical companies to undertake a risk management plan as part of post-authorization safety monitoring. SCEM studies recognize that the study population comprises those patients who may have treatment initiated under the care of specialist health care professionals and who are more complex in terms of underlying disease, co-morbidities and concomitant medications than the general disease population treated in primary care. The aims of this paper are to discuss the SCEM new-user study design, rationale and features that aim to address possible bias (such as selection bias) and current applications. [ABSTRACT FROM AUTHOR]

Background: Problematic prescription drug use is reflected by or associated with drug-seeking aberrant behaviours. Research gaps include lack of post-marketing evidence and instruments. As part of the pharmacovigilance requirements, a risk management plan was developed for fentanyl buccal tablets (FEBT) by the manufacturer, with an additional pharmacovigilance activity requested by the regulatory authority, to investigate the risks of misuse, abuse, criminal use, off-label use and accidental exposure to FEBT after the product became commercially available. A Modified Prescription-Event Monitoring (M-PEM), observational, post-authorisation safety surveillance (PASS) study was conducted, with an overall aim to examine the use of FEBT in relation to their safety as prescribed in primary care in England. One of the exploratory objectives included estimating the prevalence of aberrant behaviours during FEBT treatment.Objective: To determine the feasibility of estimating the prevalence of risk factors associated with dependence on starting treatment and aberrant behaviours in patients during treatment with a prototypical abuse liable substance (fentanyl), as based on the application of an existing index (the Chabal criteria).Methods: Data were collected as part of the M-PEM PASS study; exposure and outcome data (including risk factors for dependence and aberrant behaviours based on behavioural not clinical manifestations) were derived from questionnaires sent to primary care physicians in England during April 2008 to June 2011. For the exploratory objective of interest, descriptive statistics and simple (non-weighted) risk scores were constructed on aggregate counts (score ≥3 considered 'high-risk'). Supplementary analyses explored the relationship between the two indices and the characteristics of patients with aberrant behaviours and those without (crude odds ratios plus 95% confidence interval (CI) were calculated).Results: In a cohort of 551 patients, the prevalence of at least one pre-existing risk factor for dependence was 26% (n = 145), whilst the frequency of aberrant behaviours observed during treatment was 8% (n = 46). Patients with aberrant behaviours had several different characteristics to patients without. The two indices were associated (χ (2) df (20) = 58.72, p < 0.001), but a high-dependence risk-factor score provided a poor indication of high aberrant behaviour risk; the area under the receiver operating characteristic curve was 0.58 (95% CI 0.41, 0.74).Limitations: Study limitations included subjectivity in relation to physicians identifying aberrant behaviours, and under-reporting thereof in PASS observational study designs. The presence of these criteria does not confirm misuse, but should be considered as a signal of problematic opioid misuse, which requires investigation. Further research is needed to develop a more robust analytical construct.Conclusion: In this PASS study, the prevalence of at least one pre-existing risk factor for dependence was 26%, whilst the frequency of aberrant behaviours observed during treatment was 8%. Patients with aberrant behaviours had several different characteristics to patients without. This study demonstrates the feasibility of the systematic collection of physician reports of risk factors for dependence and aberrant behaviours to facilitate the development of risk scores, using these reports to support the post-marketing risk management of products with misuse potential. [ABSTRACT FROM AUTHOR]

Background: Varenicline (Champix), launched in the UK in December 2006, is indicated for the treatment of smoking cessation in adults (≥18 years of age). In 2008, the Medicines and Healthcare products Regulatory Agency (MHRA) in the UK issued a warning suggesting that varenicline was associated with disparate neuropsychiatric symptoms, including depression, suicidal thoughts and behaviour. In response to this regulatory warning, the Drug Safety Research Unit conducted a modified prescription-event monitoring (M-PEM) study to monitor the safety of varenicline. Objective: The aim of this study was to estimate the incidence and examine the pattern of neuropsychiatric events reported to general practitioners (GPs) in England during the immediate postmarketing period for varenicline. Methods: A postmarketing surveillance study was conducted using the observational cohort technique of M-PEM. Patients were identified from dispensed prescriptions issued by primary care physicians between December 2006 and March 2007. Data on exposure, previous history of psychiatric illness and events reported during and after treatment were collected from questionnaires. In order to determine whether hazards for neuropsychiatric events of interest (depression, anxiety, aggression, suicidal ideation, non-fatal self-harm) were non-constant over time (which could indicate a possible association with the drug), the pattern of events was examined by plotting the smoothed hazard function estimate and then fitting a Weibull model. The Weibull model shape parameter (β) and 95 % confidence interval were used as a test for a non-constant hazard function (where a value of 1 indicates a constant hazard over time). In addition to this analysis, the difference in incidence densities (IDs) between month 1 and months 2-3 were calculated and compared. Results: The cohort comprised of 12,159 patients (median age 47 years [interquartile range 19]; 56.9 % [ n = 6924 female]). The number of events reported during treatment, reason for stopping, adverse drug reactions (ADRs), and the p-value for the Weibull shape parameter were as follows: depression ( n = 94; 42; 19; p = 0.144); anxiety ( n = 94; 49; 9; p = 0.009); aggression ( n = 7; 4; 2; p = 0.465); suicidal ideation ( n = 8; 4; 1; p = 0.989) and non-fatal self-harm ( n = 5; 1; 0; p = 0.771). No differences in the IDs between months 1 and months 2-3 were found for any of the events. Conclusion: Whilst between 7 and 17 % of neuropsychiatric events were attributed to the drug by GPs and approximately 20-50 % were given as reasons for stopping, no signal was raised using the ID differences approach, and only anxiety was flagged as a potential signal for an ADR using the Weibull model. The signal for anxiety requires further evaluation to determine whether the drug plays a part in the development of anxiety or whether it is a withdrawal symptom caused by smoking cessation. Analysis methods will lack power when the numbers of events are low even when a large number of participants are included in the study. [ABSTRACT FROM AUTHOR]

Background: Modafinil (Provigil) was marketed in the UK in 1998 to promote wakefulness in the treatment of narcolepsy. In April 2004, the licence was extended to include chronic pathological conditions; 2 years later, the prescription of modafinil was restricted to patients with shift work sleep disorder, narcolepsy and obstructive sleep apnoea/hypopnoea syndrome. Following a recent review of the safety data, the licence has been further restricted to only treat patients with narcolepsy. The review highlighted the degree of off-label usage of modafinil, including patients with multiple sclerosis.Objective: The aim of this study was to examine the safety profile of modafinil in real-world clinical usage and across a range of prescribing indications, including multiple sclerosis.Methods: The study was conducted using the observational cohort technique of Modified Prescription-Event Monitoring. Patients were identified from dispensed prescriptions issued by primary care physicians from July 2004 to August 2005. Patient demographics and information on prescribing behaviour were included in the questionnaire sent to the prescribing general practitioner (GP) 6 months after the initial prescription for each patient. The questionnaire sought data on any events that patient may have experienced during that time, reasons for stopping treatment with modafinil, adverse drug reactions (ADRs), potential interaction with contraceptives, and pregnancies. Incidence densities (IDs) were calculated for all events, and stratified according to indication and dose. Specific events were evaluated by requesting further information.Results: Of the 4,023 questionnaires sent to GPs, 2,416 were returned (response rate 60.1 %). Of these, only those patients issued modafinil after April 2004 (with the associated broadening of the indications for treatment) were included in the study, resulting in a final cohort of 1,096 patients: 497 (45.3 %) male, median age of 52 years (interquartile range [IQR] 41-63), and 599 (54.7 %) female, median age of 47 years (IQR 38-57). Nine patients were aged 16 years or younger; no serious skin reactions were reported in this group. Thirty-four percent of the cohort had an indication of multiple sclerosis. In this study, the majority of the clinical events that were most frequently reported as ADRs or reasons for stopping or that occurred in month 1 have been previously documented with modafinil. The results of the study show that less than half of the women of child-bearing potential were established on a recommended contraceptive programme; three women became pregnant whilst taking modafinil and the oral contraceptive pill. Stratification of IDs by dose revealed certain additional events occurred during month 1 of treatment at the higher dose only. Assessment of individual cases of cardiac, psychiatric and skin events indicated causal associations with modafinil.Conclusions: This study provides important additional safety data on the use of modafinil in patients in 'real-world' use, including those for whom the prescribing indication is outside the terms of licence, as per recent changes to the licensed indications for treatment. In addition to safety data, our study provides useful utilization data. Results from this study indicate that a significant number of women of child-bearing potential had not been commenced on appropriate contraceptive programmes prior to starting modafinil. There were three pregnancies that occurred whilst taking contraception, highlighting the necessity of ensuring effective contraceptive cover for women during and after stopping treatment with modafinil. Analysis of the data showed that the majority of events reported as ADRs or reasons for stopping and ranked events during the first month of treatment had been previously documented with the use of modafinil. Stratification of events according to dose revealed a number of events that occurred at the higher dose only, including serious events such as psychosis. The targeted events for which causality assessments were undertaken confirmed the potential of modafinil to induce certain types of events in individual patients, including cardiac and psychiatric events. [ABSTRACT FROM AUTHOR]

Background: In 2005, spontaneous reporting of adverse drug reactions (ADRs) to the UK's Yellow Card Scheme (YCS) was extended to include patient reports. Here, we investigate the potential pharmacovigilance impact of patient reporting.Objectives: The aim of the study was to investigate the relative contribution of patient reporting to signal detection through disproportionality analysis.Methods: Data were analysed from all reports submitted directly to the YCS between October 2005 and September 2007. Three datasets of drug-ADR pairs were created: one for patient reports, one for healthcare professional (HCP) reports and one for all reports combined. The proportional reporting ratio (PRR) method was used to identify signals of disproportionate reporting (SDRs) in each dataset. The number of SDRs identified from patient and HCP reports were compared, as well as the type of ADR and suspect drug involved. A sensitivity analysis was performed to examine how combining the patient and HCP reports may affect the SDRs identified.Results: Data were received for 5,180 patient and 20,949 HCP reports, relating to 16,566 and 28,775 drug-ADR pairs, respectively, with 4,340 (10.6 %) pairs found in both datasets. A significantly higher proportion of the SDRs identified from HCP reports involved reactions classified as serious by the Medicines and Healthcare products Regulatory Agency (MHRA), compared with patient reports (n = 931, 48.0 % vs. n = 185, 28.5 %), or involved newly marketed drugs (n = 596, 30.7 % vs. n = 71, 10.9 %). The proportion of SDRs assessed as not listed on the Summary of Product Characteristics (SPC) was similar in each group (~15 %, based on a random sample). After combining the patient and HCP reports, 278 (~11 %) of the SDRs identified when each group was analysed separately no longer met the SDR criteria, including 12 potentially serious ADRs not listed on the product's SPC. On the other hand, the combined dataset identified an additional 508 SDRs that were not identified when patient or HCP reports were analysed separately. Approximately 10 % (n = 47) of these additional SDRs were assessed as serious ADRs and were not listed on the product's SPC.Conclusions: Although this study is limited to the UK experience, overall, the results suggest that patient reporting may provide a positive complementary contribution to that of HCPs. Patient reporting may make an important contribution to drug safety by identifying different SDRs not identified from HCP reports alone. The combination of reports from patients and HCPs, however, when used for the purposes of signal detection through disproportionality analysis, may result in the loss of some information. One possible strategy is to conduct such analyses using reports from patients and HCPs combined, as well as separately for each group. [ABSTRACT FROM AUTHOR]

Background: Levocetirizine was launched onto the UK market in September 2001. It is indicated for symptomatic treatment of allergic rhinitis (AR), including persistent AR and chronic idiopathic urticaria.Objective: The aim of the study was to monitor the safety of levocetirizine prescribed in the primary care setting in England, in the immediate postmarketing period.Methods: Exposure data were derived from dispensed prescriptions written by primary care physicians (general practitioners [GPs]) for levocetirizine (November 2001-November 2002): patient demographic, indication, pattern of use and outcome (event) data from enhanced prescription-event monitoring (PEM) questionnaires (with additional questions to gather further relevant information) returned by GPs. Incidence density observation rates (IDobs) [number of first reports/1000 patient-months] between months 1 and 2 (IDobs(m1/m2)) were compared for the whole cohort and by groups defined by indication and pattern of use.Results: The cohort comprised 12 367 patients (median age 37 years [interquartile range 22-55]; 58% female). The most frequent indication was AR (67%; n = 8275). After 2 months, 35.7% (n = 2414) of patients were still taking levocetirizine. 'Condition improved' was the most common event and reason for stopping treatment. Headache/migraine was uncommon but associated with starting treatment (IDobs(m1/m2) 2.4 [95% CI 1.1, 6.0]), as was drowsiness/sedation (IDobs(m1/m2) 11.5 [95% CI 4.2, 43.9]). Cardiovascular events occurred rarely or very rarely, as did most central and peripheral nervous system events. No serious adverse drug reactions (ADRs) were reported. Events related to effectiveness were more frequent in month 1 than month 2 for all patient subgroups.Conclusions: This postmarketing surveillance study shows that levocetirizine is well tolerated when used in general practice in England. No previously unrecognized ADRs were detected. This study highlights how modifications to PEM, such as additional questions, are contributing to the evaluation of drug utilization factors in relation to risks. [ABSTRACT FROM AUTHOR]

Prescription-Event Monitoring (PEM) is a well established postmarketing surveillance technique designed to monitor the overall safety of newly marketed medicines as used in real-life clinical practice, usually in cohorts of at least 10 000 patients. At the Drug Safety Research Unit in the UK we are now moving towards a more targeted safety surveillance known as Modified PEM (M-PEM). These studies combine the advantages of conventional PEM studies (in monitoring general safety and identification of unexpected risks of a medicine) with that of a more targeted safety study that addresses specific questions (to better understand known or partially known risks with a medicine). Through the use of enhanced data collection questionnaires, M-PEM expands the range of applications of conventional PEM, which include more detailed characterization of real-life drug use, adherence to prescribing recommendations and targeted analysis of events requiring special monitoring by regulatory authorities. A particularly useful application is the evaluation of the safety of a medicine in special populations or subgroups (e.g. patients switching from another therapy or patients with a particular risk factor) or following important changes in the product's lifecycle (e.g. a licensing or formulation change).M-PEM studies therefore have an important contribution to make to pharmacovigilance and the risk management of medicines by providing valuable information on the use of new medications under real-life situations. [ABSTRACT FROM AUTHOR]

Background: Marketing authorization for rimonabant was withdrawn in October 2008, mainly because the psychiatric adverse effects could not be addressed by further risk minimization.Objective: The aim of the study was to compare the risk of major and minor depressive episodes in the 6 months prior to and the 6 months after starting treatment with rimonabant.Methods: We conducted a before and after study using the observational cohort technique of Modified Prescription Event Monitoring to compare the risk of major and minor depressive episodes in new users of rimonabant reported in the 6 months before to the 6 months after starting treatment with rimonabant. Patients were identified from dispensed prescriptions issued by primary care physicians from June 2006 to October 2008. Patient demographics and information on depressive episodes were requested 6 months after the date of the first prescription for each patient. Risk ratios (RR) were calculated by comparing before and after events using a matched analysis.Results: The cohort comprised 10,011 patients. The number of patients who had major depressive episodes before and after starting treatment were 147 and 168, respectively (RR 1.14; 95% CI 0.94, 1.39) and the number of patients who had minor depressive episodes were 825 and 829, respectively (RR 1.00; 95% CI 0.93, 1.10). For patients who had a previous history of psychiatric illness (n = 1132), 91 and 73, respectively, experienced major depressive episodes (RR 0.80; 95% CI 0.62, 1.03), and 367 and 220, respectively, experienced minor depressive episodes (RR 0.59; 95% CI 0.53, 0.68). For patients without a previous history of psychiatric illness (n = 8879), 56 and 95, respectively, experienced major depressive episodes (RR 1.7; 95% CI 1.2, 2.3), and 458 and 609, respectively, experienced minor depressive episodes (RR 1.33; 95% CI 1.20, 1.48).Conclusions: When comparing all patients in the cohort, there was no increased risk of developing a depressive episode whilst taking rimonabant. However, when considering subsets of patients with and without a previous history of psychiatric illness, the risk profiles were different. In patients without a previous history of psychiatric illness, there were more depressive episodes in the 6 months after starting treatment compared with the 6 months before starting treatment with rimonabant. [ABSTRACT FROM AUTHOR]

Background: Using postmarketing pharmacovigilance data collected shortly after market authorization of lamotrigine in the UK, a study was conducted to compare the adverse event (AE) profiles of children and adults taking lamotrigine, using modified signal detection methods.Methods: Data from the lamotrigine Prescription Event Monitoring (PEM) study, an observational cohort study, were stratified by age and examined using summary statistics for adverse drug reactions (ADRs), reasons for stopping treatment, deaths and follow-up information. Incidence densities of AEs in children (0-17 years) and adults (> or =18 years) in the first month of treatment were compared with months 2-6 to examine whether the AE rates were different in these two periods. AE rates in children were compared with those in adults (proportional reporting ratio [PRR] and incidence rate ratios), to compare the AE profiles between these age groups.Results: The cohort included 2457 children and 7379 adults. Differences in the AE profiles between children and adults were observed. Rash (PRR 1.2) and Stevens-Johnson syndrome (PRR 4.5) were more commonly reported in children, and confusion more frequently in adults (PRR 6.3). In children, 33% of ADRs were reported to the Regulatory Authority compared with 44% in adults. A higher proportion of children stopped treatment due to lack of effectiveness (45% vs 38%). No deaths were attributed to lamotrigine.Conclusions: This study demonstrated that signal detection methods can be used to detect quantitative and qualitative differences in the AE profiles between the first children and adults taking a newly licensed drug. [ABSTRACT FROM AUTHOR]

Background: Strontium ranelate is indicated for the treatment of postmenopausal osteoporosis. An association between strontium ranelate and venous thromboembolism (VTE) was identified in an analysis of phase III clinical trials.Objective: To estimate the incidence of VTE in patients within the strontium ranelate (Protelos(R)) Prescription-Event Monitoring (PEM) study cohort during the first 12 months after starting treatment.Methods: Patients in this analysis were identified from dispensed prescriptions that had been issued by general practitioners (GPs) in England for strontium ranelate between October 2004 and January 2008. For each individual patient, a Green Form questionnaire was sent to their GP 12 months after the date of the first prescription issued for strontium ranelate, requesting information about the patient including start and stop dates of treatment (if stopped), age, sex, indication, any history of VTE events, reasons for stopping and whether the patient had any events since starting the drug. VTE was defined as reports of deep vein thrombosis (DVT) or pulmonary embolism (PE). The crude incidence of VTE was calculated for events that occurred during the first 12 months after starting treatment (plus 30 days after stopping), with 95% Poisson exact CIs for the whole cohort, and subsets defined by age and past history of VTE.Results: The final analysis cohort consisted of 10 782 patients. Where specified, mean age was 73.3 years (SD 11.45) [n = 10 696]; 9833 (91.3%) were female and 934 (8.7%) were male. Where the history of VTE was specified, 233 patients (2.6%) had a history of VTE prior to starting. In the first 12-month period, there were 48 incident reports of VTE (DVT or PE) during treatment (or within 30 days of stopping) in the cohort, with 7696.89 years of exposure, giving a crude incidence rate of VTE of 6.24 cases (95% CI 4.60, 8.27) per 1000 patient-years exposed.Conclusions: This analysis has provided an estimate of the incidence of VTE in patients treated with strontium ranelate in the general practice setting. The rate is similar to estimates in populations of similar age and corresponds to the incidence found in patients from phase III clinical studies and observational cohort studies of strontium ranelate on this topic. The crude annual incidence rate of VTE in the PEM cohort is higher than the background annual incidence rate found in the UK population, but is similar to estimates in populations of similar age and populations receiving treatment for postmenopausal osteoporosis. Also, we acknowledge the potential for underestimating the incidence in this population. Nevertheless, this analysis contributes to the ongoing postmarketing safety assessment of this product. [ABSTRACT FROM AUTHOR]

Background: Intrinsa is a transdermal testosterone patch that is indicated for use in hypoactive sexual desire disorder (HSDD) in women who have undergone bilateral oophorectomy and hysterectomy (surgically-induced menopause) receiving concomitant oestrogen therapy.Objective: To describe the utilization characteristics of the patients prescribed testosterone patch (Intrinsa) based on an interim analysis of an ongoing Prescription-Event Monitoring study in England, and to assess, where possible, if the product is being used within the licensed therapeutic indication.Methods: In this interim analysis, patients were identified from dispensed prescriptions that had been issued by general practitioners (GPs) for Intrinsa from March 2007. 'Green form' questionnaires were sent to GPs 6 months following the date of the first prescription for Intrinsa for each individual patient, requesting information including age, sex, start and stop dates of treatment (if stopped), prescribing indication and reasons for stopping. Additional questions were asked regarding the patient's menopausal status and use of concomitant oestrogen therapy.Results: The interim cohort consisted of 756 patients. The majority of patients were reported to be female (746 [98.7%]) with a median (interquartile range) age of 50 years (44-55 years). The most commonly reported indication was the licensed indication of HSDD in 580 patients (76.7%). Just under one-half of the patients (n = 364 [48.1%]) were reported to have been hysterectomized and bilaterally oophorectomized (surgically-induced menopause) prior to starting Intrinsa; 127 patients (16.8%) were naturally menopausal. For 222 patients (29.4%) the GP specified that the patient was not using concomitant oestrogen therapy. Overall, only 219 patients (29.0%) in the cohort were being prescribed Intrinsa according to the manufacturer's recommendations.Conclusions: This study has highlighted that some clinicians are prescribing this product outside the recommended terms of the licence, with less than 30% of patients receiving Intrinsa according to prescribing guidelines. All events experienced by these patients will be analysed to detect any possible adverse events from using Intrinsa outside of the licensed therapeutic indication. The findings support the ongoing postmarketing risk management of the product. [ABSTRACT FROM AUTHOR]

Background: Varenicline tartrate (Champix), a new smoking cessation medicine, was launched in the UK in December 2006. Varenicline is a highly selective partial agonist of the alpha(4)beta(2) nicotinic acetylcholine receptor (alpha(4)beta(2) receptor). The partial agonistic binding leads to alleviation of symptoms of craving and withdrawal, and simultaneously prevents nicotine from binding to the alpha(4)beta(2) receptor thereby causing reduction in the rewarding and reinforcing effects of smoking. Regulatory concerns have arisen about psychiatric events associated with varenicline, including depression, suicidal ideation and changes in behaviour/emotion.Aim: To present the interim results of an ongoing study by the Drug Safety Research Unit (DSRU) monitoring the safety of varenicline.Methods: The observational cohort study is being conducted to study the postmarketing safety of varenicline, using modified prescription-event monitoring (PEM) methodology. Patients are identified from dispensed prescriptions issued by general practitioners (GPs) from December 2006. Demographic, clinical event (during the course and 1 month after stopping varenicline, reasons for discontinuing and suspected adverse drug reactions [ADRs] to varenicline) and drug utilization data are collected from detailed study-specific questionnaires posted to GPs at least 4 months after the date of first prescription for each patient. Event incidence densities (IDs; number of first reports of an event/1000 patient-months of exposure) are calculated.Results: The interim cohort comprises 2,682 patients: median age 47 years (interquartile range [IQR] 38-56), 60.7% females (n = 1627). Nausea/vomiting was the most frequent clinical reason for stopping varenicline (n = 91; 35.3% of clinical reasons) and the most frequently reported suspected ADR to varenicline (n = 60, 50.9% of patients for whom an ADR was reported). The most frequently reported psychiatric events (causality not implied) during treatment included (n; % of cohort): sleep disorder (43; 1.6%), anxiety (33; 1.2%), depression (29; 1.1%), abnormal dreams (26; 1.0%) and mood change (17; 0.6%). Two cases of attempted suicide were reported during treatment with varenicline (one patient took an overdose of a benzodiazepine with alcohol, the other slashed their wrist). Both these patients had previous history of psychiatric illness and precipitating factors for the event.Conclusion: This study reflects 'real life' use of varenicline. Nausea/vomiting - the event most frequently reported as an ADR and as reason for stopping treatment - is listed in the UK Summary of Product Characteristics (SPC). The most frequently reported psychiatric events are listed in the UK SPC. All patients with suicidal events either had a past medical history of psychiatric illness prior to starting varenicline and/or a precipitating factor for the event. Clinicians should closely monitor patients with pre-existing psychiatric illness who are taking varenicline. Further evaluation of events of interest including psychiatric events is ongoing. Results presented are expected to change as the cohort size increases. Results of this study should be taken into account together with other clinical and pharmacoepidemiological studies. [ABSTRACT FROM AUTHOR]

Background: Hypoglycaemia is an acute complication associated with intensive treatment of patients with diabetes mellitus. This complication poses a major challenge in diabetes management. Furthermore, severe hypoglycaemia may be life threatening. Although hypoglycaemia is more often associated with insulin treatment, oral hypoglycaemic agents have the potential to trigger hypoglycaemia.Aim: The aim of this study was to quantify the incidence of hypoglycaemic events and to describe the pattern of these incident events during the first 9 months of treatment with four oral antidiabetic drugs, rosiglitazone, pioglitazone, nateglinide and repaglinide, prescribed in general practice in England.Methods: We used data collected for prescription-event monitoring (PEM) studies of rosiglitazone, pioglitazone, nateglinide and repaglinide. PEM is an observational, non-interventional, incept cohort study. Observation time for each patient and incidence rate (IR) per 1000 patient-years of treatment for hypoglycaemia was calculated for each drug cohort. Smoothed hazard estimates were plotted over time. Case/non-case analysis was performed to describe and compare patients who had at least one hypoglycaemic event in the first 9 months of treatment with those who did not.Results: The total number of patients included in the analysis was 14,373, 12,768, 4,549 and 5,727 in rosiglitazone, pioglitazone, nateglinide and repaglinide cohorts, respectively. From these, 276 patients experienced at least one episode of hypoglycaemia. The IR was between 50% and 100% higher in patients receiving treatment with meglitinides compared with those treated with the thiazolidinediones (TZDs) [IR = 9.94, 9.64, 15.71 and 20.32 per 1,000 patient-years for rosiglitazone, pioglitazone, nateglinide and repaglinide, respectively]. The plot of the hazard function and the estimated shape parameter from the Weibull regression model showed that pioglitazone, nateglinide and repaglinide had non-constant (decreasing) hazards over time, whereas the hazard for rosiglitazone-treated patients was approximately constant over time. Nateglinide and repaglinide had similar shape hazard function, indicating a significantly higher number of hypoglycaemic episodes shortly after starting treatment. For women treated with TZDs, hypoglycaemia was reported more frequently than for men.Conclusion: This analysis shows that the frequency of reported hypoglycaemia within the study cohorts was relatively low. The rates of hypoglycaemia were not equal between drug classes. Treatment with nateglinide or repaglinide was characterized by a higher incidence of hypoglycaemia at the beginning of treatment. Further investigation is necessary to assess whether women treated with TZDs are more prone to hypoglycaemia than men. Findings from this study should be taken into account with other clinical and pharmacoepidemiological studies. [ABSTRACT FROM AUTHOR]

Background: Pioglitazone is an antidiabetic drug that belongs to the thiazolidinedione (TZD) class of insulin-sensitizing agents. Adverse events to pioglitazone of potential severity are listed in the 'special warnings and special precautions for use' section of the pioglitazone summary of product characteristics (SPC), with recommendations for monitoring and management.Objective: To describe the risk management and outcomes of recognized TZD class effects in patients prescribed pioglitazone.Methods: An observational study of risk management and event outcomes for the adverse events of cardiac failure, fluid retention/oedema, weight gain, anaemia and abnormal liver function tests (LFTs) was performed. Patients were identified from within a prescription-event monitoring (PEM) postmarketing cohort of first-users of pioglitazone. Patients with pre-existing events or alternative causes, or with no possibility of collecting further information, were excluded. Outcomes included (i) the method of detection of the adverse event, i.e. whether the patient or the prescriber identified the problem; (ii) whether responsibility for risk management was taken at a primary- or secondary-care level; (iii) interventions taken to manage the event, including discontinuation of treatment; (iv) resolution and/or other outcomes of the event; and (v) general practitioner (GP) opinion of relatedness of the event to pioglitazone.Results: Acute events such as cardiac failure and oedema were more likely to be detected by the patient presenting with the event rather than at regular follow-up. GPs were more likely to take responsibility for management of abnormal LFTs, anaemia and oedema events, whereas hospital admissions occurred mainly in patients with cardiac failure (45.3%). Pioglitazone was stopped in more than 50% of each type of event, apart from anaemia. Oedema events were the most likely to resolve (87.6%) and anaemia the least likely (42.9%). Oedema events were the most likely to be attributed to the drug by GPs, whereas cardiac failure was the event least attributed to pioglitazone.Conclusions: Timely drug withdrawal and/or interventions such as corrective treatment or referral to a specialist can lead to successful resolution of class-effect adverse events of pioglitazone. Regular follow-up of patients on antidiabetic agents is essential to detect certain events, but more acute events are more likely to be reported spontaneously. Treatment options for patients with diabetes mellitus and cardiovascular risk factors are limited, requiring careful benefit-risk assessment of pioglitazone use in these patients and careful monitoring for signs of worsening cardiac function. [ABSTRACT FROM AUTHOR]

Background: Desloratadine is a non-sedating, long-acting histamine H(1) receptor antagonist indicated for the symptomatic relief of allergic rhinitis (AR) and chronic idiopathic urticaria in patients aged>12 years.Objective: To monitor the safety of desloratadine as prescribed in England, using the observational cohort technique of prescription event monitoring (PEM).Methods: Exposure data were derived from dispensed prescriptions written by primary care physicians (general practitioners [GPs]) for desloratadine (March-May 2001); patient demographics, indication, pattern of use and outcome (event) data were obtained via simple questionnaires returned by GPs. Incidence density observation rates (IDobs) were calculated to compare the difference in event rates between months 1 and 2 (m1/m2) and were compared for the whole cohort and by groups defined by indication and pattern of use.Results: The cohort comprised 11 828 patients (median age 37 years [interquartile range 22, 54]; 59.9% were female). The most frequent indication was AR (n=8001; 67.6%). After 2 months, 36.8% (n=2464) of patients were still taking desloratadine. 'Condition improved' was the most common event and reason for stopping. Headache/migraine was uncommon but associated with starting treatment (IDobs(m1/m2) ratio 3.99 [95% CI 1.70, 10.83]). Cardiovascular events occurred rarely or very rarely, as did central and peripheral nervous system events. No serious adverse drug reactions (ADRs) were reported. Events related to effectiveness were more frequent in month 1 than month 2 for all patient subgroups.Conclusions: This postmarketing surveillance study shows that desloratadine is well tolerated when used in general practice in England. No previously unrecognized ADRs were detected. This study highlights how modifications to PEM are contributing to the evaluation of drug utilization factors in relation to risks. [ABSTRACT FROM AUTHOR]

Background: In the UK, the licence for carvedilol was extended in 1998 to include symptomatic heart failure (New York Heart Association [NYHA] class II and III heart failure) with the recommendation that initiation and up-titration should be under the supervision of a hospital physician. A post-marketing surveillance study was conducted to address the UK regulatory authority's request for monitoring the use and safety of carvedilol prescribed for heart failure in clinical practice.Aim: To investigate adherence to risk management recommendations for the use of carvedilol for heart failure, monitor how patients' subsequent care was managed and collect event data to evaluate the safety profile of carvedilol used for the treatment of heart failure.Methods: An observational cohort study using a modified prescription-event monitoring technique identified patients from dispensed primary care prescriptions in England (August 1999 to June 2001). An eligibility questionnaire was used to identify patients who had been prescribed carvedilol for heart failure for the first time after 31 July 1999. Up to three follow-up questionnaires were sent to the prescribers of eligible patients, requesting demographic information, dosage, supervision of treatment, status of cardiac failure and event information.Results: 2311 patients met the eligibility criteria. For 1666 patients, one or more valid follow-up questionnaires were returned: 68.5% were male; male median age 66 years; female median age 72 years; the observation period was up to 3 years. Hospital physicians supervised initiation of treatment and first up-titration in 85.6% and 61.4% of patients, respectively. 49.2% of patients were prescribed the recommended starting dosage of carvedilol (6.25 mg/day). Approximately 25% of patients started on a lower dose than recommended, and the same proportion were prescribed a higher dose. NYHA status of cardiac failure between starting treatment and the third questionnaire improved for 39.5% of patients, deteriorated for 10.9%, and 11.7% of those for whom NYHA status was given died. Adverse drug reactions (ADRs) were reported for 2.4% of patients; the most commonly reported ADR was malaise/lassitude. Overall, 27.1% of patients stopped taking carvedilol. None of the 163 deaths were attributed to carvedilol.Conclusions: Regulatory guidelines for the use and risk management of carvedilol in heart failure were mostly followed, and most patients appeared to benefit from treatment with carvedilol for heart failure. Malaise/lassitude was the main reason for discontinuing treatment. Further investigations may be warranted to examine the prescribing of carvedilol at lower than recommended doses. [ABSTRACT FROM AUTHOR]

Background: Pioglitazone is an antidiabetic drug that targets insulin resistance in patients with type 2 diabetes mellitus by stimulating the peroxisome proliferator-activated receptor (PPAR)-gamma. Pioglitazone belongs to a class of drugs called thiazolidinediones (TZDs) and was launched in the UK in November 2000.Objective: To monitor, using prescription-event monitoring, the post-marketing safety of pioglitazone, which is prescribed in primary care in England.Methods: An observational cohort study in which patients were identified from dispensed prescriptions issued by primary-care physicians/general practitioners (GPs) between November 2000 and June 2001. Information on demographics, the use of pioglitazone, clinical event data, events suspected as adverse drug reactions, reasons for stopping the drug and cause of death (if appropriate) were collected using questionnaires posted to GPs at least 8 months after the date of first prescription for each patient. Event incidence densities (IDs) [number of first reports of an event/1000 patient-months of exposure] were calculated.Results: The cohort comprised 12 772 patients (median age 62 years); 53.1% were males. The most frequent starting daily dose of pioglitazone was either 15 mg or 30 mg (n = 10 298). Pioglitazone/metformin was the most frequently used combination reported (n = 4029). Of the 3690 patients who stopped treatment, 1143 stopped due to reasons related to poor glycaemic control. 'Oedema/fluid retention' (n = 121) and 'weight gain' (n = 118) also appeared high on the list of reasons for discontinuing. 'Malaise/lassitude' and 'nausea/vomiting' were the most frequently reported suspected adverse drug reactions (ADRs) associated with pioglitazone. Specific clinical events considered as early onset events with pioglitazone were: 'malaise/lassitude', 'nausea/vomiting', 'dizziness', 'headache/migraine', 'diarrhoea', 'weight gain' and 'abnormal liver function test'.Conclusion: Pioglitazone was considered to be a reasonably well tolerated drug, with the main reasons for discontinuing being related to the drug not being effective. The frequency of individual ADRs reported in this study did not exceed the frequency in the summary of product characteristics (SPC) for pioglitazone. However, amongst the frequently reported suspected ADRs, 'nausea/vomiting' and 'diarrhoea' are not listed in the SPC. Further research is required to assess whether the risk of myocardial infarction and deaths due to cardiovascular causes is a class effect of the thiazolidinediones. Results from this study should be taken into account with other clinical and pharmacoepidemiological studies. [ABSTRACT FROM AUTHOR]

Objective: Esomeprazole, the S-isomer of omeprazole, was launched in the UK in September 2000. The first proton pump inhibitor, omeprazole, has been marketed in the UK for over 10 years. However, the adverse event database of newly marketed drugs is limited, and it is only after widespread clinical use that the adverse effect profile of a drug is ascertained more comprehensively. This study aims to monitor the safety of esomeprazole prescribed in the primary care setting in England using prescription-event monitoring (PEM).Methods: A postmarketing surveillance study using the observational cohort technique of PEM. Patients were identified from dispensed prescriptions for esomeprazole issued by general practitioners between September 2000 and April 2001. Questionnaires ('green forms') requesting clinical event data on these patients were sent to prescribers approximately 6 months after the date of the first dispensed prescription for each individual patient. Incidence densities (IDs), expressed as the number of first reports of an event/1000 patient-months of exposure (PME), were calculated. Significant differences between IDs for events reported in the first month (ID1) and the following 5 months (ID2-6) of exposure were regarded as potential signals. Other methods for signal detection such as medical evaluation of selected events and evaluation of reasons for stopping were also applied.Results: Green forms containing clinically useful information for 11 595 patients (median age 56 years; 53.2% female) were received. Diarrhoea was the event with the highest ID1 in month 1 (8.0 per 1000 patient months of exposure). Adverse events that occurred significantly more often in the first month of treatment with esomeprazole compared with months 2-6 included diarrhoea, nausea/vomiting, abdominal pain, dyspepsia, headache/migraine, intolerance, malaise/lassitude, pruritus, unspecified adverse effects and abnormal sensation.Conclusions: The safety profile of esomeprazole was consistent with the prescribing information and experience reported in the literature. [ABSTRACT FROM AUTHOR]

BACKGROUND: Newly approved drugs, in comparison with older drugs, are more often prescribed to patients who have not responded satisfactorily to established related drugs or as first-line therapy to patients with a high baseline risk for adverse outcomes (i.e. channelling). However, these patients are less likely to benefit from the prescribed drug and/or are more prone to adverse drug reactions. Therefore, it is difficult to unravel whether observed risks or increases in risk of new drugs are real, i.e. related to the pharmacology, or whether these are related to selective prescribing to patients who are more susceptible to adverse events because of some underlying risk factor(s). The channelling paradox may exist for cyclo-oxygenase (COX)-2 selective inhibitors (‘coxibs’) instead of traditional nonselective NSAIDs in relation to both gastrointestinal (GI) and cardiovascular (CV) safety. OBJECTIVE: To evaluate the risk profiles for GI and CV adverse effects in nonselective NSAID and coxib new-user populations over time, in terms of a quantitative measure since the introduction of coxibs. METHODS: This was a population-based cohort study using the Dutch pharmaceutical claims database (Foundation for Pharmaceutical Statistics). Eligible patients (≥18 years) were those where the date of their first prescription (index date) of an NSAID (first-line [e.g. ibuprofen] or second-line [e.g. piroxicam] nonselective NSAID, COX-2 preferential NSAID or coxib) was between January 1999 and December 2003. For each patient, GI and CV risk profiles at index date were defined by a cumulative score derived from dispensing data (patient age, sex and history of medication use within 6 months of index date). Risk scores were categorized as low (score = 0), medium (1) or high (2+). Patients were recorded as switchers based on other NSAID use prior to the index date. Other information collected included the Chronic Disease Score (CDS). Crude odds ratios (ORs) were calculated for risk factors for each NSAID group versus first-line nonselective NSAID users as the reference cohort. The effect of calendar time was examined by plotting mean CV or GI risk score by quarter-year. Correlation between GI and CV scores was examined using the Pearson correlation coefficient (R). Data were stratified by patients’ history of switching. RESULTS: The four cohorts comprised patients using: first-line nonselective NSAIDs (n = 42 750); second-line nonselective NSAIDs (n = 1771); COX-2 preferential NSAIDs (n = 3661) and coxibs (n = 4861) patients. New coxib users were most likely to have high GI and CV risk scores (OR 5.3 [95% CI 5.0, 5.6] and OR 2.2 [95% CI 2.1, 2.4], respectively). At the individual patient level, GI and CV risk profiles were moderately well correlated for all NSAID cohorts (R range 0.48 to 0.62). There was no remarkable change in mean GI or CV risk profile of patients over calendar time since the market introduction of coxibs. DISCUSSION: Of the four NSAID cohorts, new coxib users tended to have the highest numbers of GI and CV risk factors, with no obvious change over calendar time. There was also evidence of correlation between GI and CV risk scores. Thus, selective prescribing of coxibs applies to people with co-existing CV as well as GI risk factors. This is important when comparing the safety and/or efficacy of new therapies to existing therapies, and emphasizes the difficulties encountered by prescribers in assessing levels of risk when initiating coxib treatment. [ABSTRACT FROM AUTHOR]

Introduction: Monitoring was required for the introduction of non-chlorofluorocarbon (CFC) propellants in metered dose inhalers (MDIs) to ensure that there were no unexpected adverse events due to the new products. A postmarketing surveillance study has been conducted to evaluate the introduction of the MDI Seretide Evohaler™ (hydrofluoroalkane-134a inhaler containing salmeterol and fluticasone propionate). Objectives: To summarise the modified prescription-event monitoring (PEM) study conducted to evaluate the introduction of Seretide Evohaler™ and discuss the relevance of this type of study towards pharmacovigilance risk-management planning. Methods: Modified PEM methodology was used to examine the introduction of Seretide Evohaler™ into general practice in England. Patients were identified from the first National Health Service prescriptions dispensed in England for Seretide Evohaler™. One postal questionnaire was sent to the prescribing doctor, requesting demographic information, severity of the indication, concomitant medication for this condition, smoking history, event data 3 months prior to and 3 months after the first prescription for Seretide Evohaler™ and also reason for stopping if it had been stopped. Pregnancies, deaths and selected events were followed up. Incidence density ratios were calculated to compare event rates 3 months prior to and 3 months after the introduction of Seretide Evohaler™. A matched cohort analysis examined oral corticosteroid use and hospital admissions between the pre- and post-exposure periods. Results: The cohort comprised 13 464 patients prescribed Seretide Evohaler™, with a response rate of 62%. There was no significant difference in the length of courses of oral corticosteroid use when the pre- and post-exposure periods were compared. A matched cohort analysis showed there was no increase in the use of oral corticosteroids (relative risk [RR] 0.95; 95% CI 0.90, 0.99) or hospital admissions in the post-exposure period (RR 0.87; 95% CI 0.73, 1.04). When the number of patients with events were compared for the periods 3 months before and 3 months after exposure, fewer events were reported in the post-exposure period. There were 64 patients who experienced adverse events within an hour of using Seretide Evohaler™, including one report of paradoxical bronchospasm and one of myocardial infarction with fatal outcome that were both assessed as possibly related to treatment. Discussion: The results of the study suggest that the introduction of Seretide Evohaler™ was generally well tolerated. The modified methodology has allowed a comparison of the event rates before and after the introduction of this CFC-free inhaler into general practice. [ABSTRACT FROM AUTHOR]

The article discusses the implication of signal detection in pharmacovigilance. Spontaneous reporting is an important source for signal detection in pharmacovigilance where it is the only source used to detect rare adverse drug reactions (ADRs). Automated signal detection can be used as a complementary method to the other methods of signal detection and can be best used in observational studies, drug use studies and clinical trials. It has evolved from research and development into practical application and it required methodological research to evaluate its effectiveness and define its role in the pharmacovigilance process.

Objectives: A prescription event monitoring (PEM) postmarketing surveillance study was carried out to examine the safety of zafirlukast as used in general practice in England.Methods: Exposure data were obtained from the first National Health Service (NHS) prescription dispensed for patients whose prescription details were processed by the Prescription Pricing Authority between August 1998 and December 2000. Outcome data were obtained from 'green form' questionnaires sent to general practitioners (GPs) at least 6 months following the first prescription issued. Incidence densities (IDs) were calculated for events reported per 1000 months of patient exposure and ID differences between the first month of treatment and months 2-6 combined were analysed. Events of medical interest were followed up by postal questionnaire sent to GPs.Results: 21 557 green forms were sent to 8051 doctors, of which 9124 (42.3%) were returned. Useful clinical data was obtained for 7976 patients of which 4664 (58.5%) were female and 3265 (40.9%) were male. The patient's sex was not specified in 47 (0.6%) forms. The median age of the cohort was 53 years (interquartile range 38-66 years). The most frequently reported primary indication was the licensed indication of asthma, but for a small proportion of the cohort it was prescribed 'off label'.A total of 152 events in 120 (1.5%) patients were reported as adverse drug reactions (ADRs) by GPs on the green forms. ADRs with the highest reported frequency were headache and nausea. There were 3514 reasons for stopping zafirlukast in 3148 (39.5%) patients, the most frequently reported of which was that the drug was 'ineffective' (2008 patients; 25.2%). The most frequently reported specified clinical reason for stopping was headache (82 patients; 1.0%). There were 28 pregnancies reported in this cohort, 20 of which were reported to have exposure to zafirlukast during the first trimester. Nine live births with no recorded congenital abnormalities were reported for pregnancies with exposure in the first trimester. There were 151 deaths reported during the study period (1.9%). The most frequently reported causes of death were related to the respiratory system (57; 37.7%), including chronic obstructive pulmonary disease, asthma and bronchopneumonia.Conclusion: This study showed that zafirlukast, as used in general practice in England, is a generally well tolerated drug with few associated adverse events. [ABSTRACT FROM AUTHOR]

Objectives: A prescription event monitoring (PEM) postmarketing surveillance study was carried out to examine the safety of zafirlukast as used in general practice in England. Methods: Exposure data were obtained from the first National Health Service (NHS) prescription dispensed for patients whose prescription details were processed by the Prescription Pricing Authority between August 1998 and December 2000. Outcome data were obtained from ‘green form’ questionnaires sent to general practitioners (GPs) at least 6 months following the first prescription issued. Incidence densities (IDs) were calculated for events reported per 1000 months of patient exposure and ID differences between the first month of treatment and months 2–6 combined were analysed. Events of medical interest were followed up by postal questionnaire sent to GPs. Results: 21 557 green forms were sent to 8051 doctors, of which 9124 (42.3%) were returned. Useful clinical data was obtained for 7976 patients of which 4664 (58.5%) were female and 3265 (40.9%) were male. The patient's sex was not specified in 47 (0.6%) forms. The median age of the cohort was 53 years (interquartile range 38–66 years). The most frequently reported primary indication was the licensed indication of asthma, but for a small proportion of the cohort it was prescribed ‘off label’. A total of 152 events in 120 (1.5%) patients were reported as adverse drug reactions (ADRs) by GPs on the green forms. ADRs with the highest reported frequency were headache and nausea. There were 3514 reasons for stopping zafirlukast in 3148 (39.5%) patients, the most frequently reported of which was that the drug was ‘ineffective’ (2008 patients; 25.2%). The most frequently reported specified clinical reason for stopping was headache (82 patients; 1.0%). There were 28 pregnancies reported in this cohort, 20 of which were reported to have exposure to zafirlukast during the first trimester. Nine live births with no recorded congenital abnormalities were reported for pregnancies with exposure in the first trimester. There were 151 deaths reported during the study period (1.9%). The most frequently reported causes of death were related to the respiratory system (57; 37.7%), including chronic obstructive pulmonary disease, asthma and bronchopneumonia. Conclusion: This study showed that zafirlukast, as used in general practice in England, is a generally well tolerated drug with few associated adverse events. [ABSTRACT FROM AUTHOR]

Introduction: The Bradford Hill criteria are a widely used, useful tool for the assessment of biomedical causation. We have examined their application to pharmacovigilance using the example of cisapride-induced QTc interval prolongation/arrhythmia.Methods: A literature search was conducted using MEDLINE, EMBASE, Reactions Weekly and regulatory websites to identify evidence for the association between cisapride and QTc interval prolongation/arrhythmia that had been published in the English language. Two hundred and five publications were identified as being potentially suitable for the study. After excluding irrelevant articles, studies on high-risk populations and review articles, 70 publications were assessed using the Bradford Hill criteria. These included 24 case reports, case series or spontaneous report summaries; eight epidemiological studies; 22 clinical studies; and 16 experimental (in vivo and in vitro) publications.Results: The most compelling evidence for an association between cisapride use and QTc interval prolongation/arrhythmia came from case/spontaneous reports and biological plausibility. Considering the rare incidence of serious cardiac events, these criteria formed the basis for the strength of the association. The number of reports from different populations showed consistency. Specificity was supported by clinical and cardiographic characterisation of the events. There were temporal relationships between the events and the initiation of cisapride treatment, increases in the dosage and the receipt of interacting medications. The relationships between the adverse events and the latter two factors exhibited biological gradients. Experimental evidence could be found from biological models, as well as reports of positive dechallenge and/or rechallenge found in individual patients. Cisapride was found to bind the human ether-a-go-go-related gene (HERG) potassium channel, which provides a plausible mechanism for QTc interval prolongation/arrhythmia. Other QTc interval-prolonging/arrhythmic drugs that also bind to HERG provided an analogy for cisapride causing QTc interval prolongation/arrhythmia via this mechanism. The evidence provided by clinical studies was inconsistent, and epidemiological studies failed to demonstrate an association. Nevertheless, this did not prevent the assessment of causation.Discussion: This study showed how different types of evidence found in pharmacovigilance can be evaluated using the Bradford Hill criteria. Further work is required to examine how the criteria can be applied to different types of adverse events and how they may be applied to pharmacovigilance. [ABSTRACT FROM AUTHOR]

Background and Objective: Rosuvastatin is a lipid-lowering drug, the newest of a class of drugs called HMG-CoA reductase inhibitors, or 'statins', launched in the UK in March 2003. Our objective was to monitor the post-marketing safety of this drug, prescribed in primary care in England, using prescription-event monitoring.Methods: An observational cohort study in which patients were identified from dispensed prescriptions issued by primary care physicians/general practitioners (GPs) between August and December 2003. Demographic and clinical-event data were collected from questionnaires posted to GPs at least 6 months after the date of first prescription for each patient. Stratified analysis of specific events by starting dose of rosuvastatin was conducted. Follow-up and causality assessment of medically significant events was undertaken.Results: The cohort comprised 11,680 patients (median age 64 years); 50.3% were males (5880 of 11,680). The median period of treatment was 9.8 months. Of these patients, 72.7% (n = 8494) were started on rosuvastatin 10 mg/day. A total of 17.5% (n = 2047) of the patients were reported to have stopped treatment with rosuvastatin. Myalgia was the most frequent reason for stopping rosuvastatin and the most frequently reported clinical event. A 2.5-fold increase in the rate of abnormal liver-function tests (LFTs) was observed for patients started on rosuvastatin 40 mg/day compared with those started on 10 mg/day (2.71; 95% CI 1.53, 4.53). No case of rhabdomyolysis was reported in this cohort.Conclusion: Rosuvastatin was considered to be a reasonably well tolerated drug. In the majority of patients, rosuvastatin was prescribed in line with recommendations. Abnormality of LFTs was found to be more frequent with the 40 mg/day dosage of rosuvastatin. Results from this study should be taken into account together with those of other clinical and pharmacoepidemiological studies of rosuvastatin. [ABSTRACT FROM AUTHOR]

Background and objectives: Desloratadine and levocetirizine are histamine H1 receptor antagonists (antihistamines) that were launched in the UK in 2001. Our objective was to compare the frequency with which drowsiness and sedation were reported for desloratadine and levocetirizine within the first 30 days of observation, as monitored using the observational cohort technique of prescription-event monitoring (PEM). Methods: Exposure data were derived from dispensed prescriptions written by primary care physicians and outcome data were derived from questionnaires that were posted to prescribers at least 6 months after the date of the first prescription for each patient. The odds ratio (OR) was calculated using unconditional logistic regression modelling. The effect of age, sex, reported prescribing indication (allergic rhinitis with asthma/wheezing, allergic rhinitis without asthma/wheezing, ‘other’), pattern of use and reported previous antihistamine use on the OR was examined. A time-to-event analysis was performed. Results: The cohorts comprised >24 000 patients in total. Cohort demographics were similar (both cohorts: median age 37 years; 60% women); the most frequently reported prescribing indication for both drugs was allergic rhinitis without asthma/wheezing (54%). The incidence of first reports of drowsiness/sedation for levocetirizine or desloratadine was low (46 [0.37%] and 9 [0.08%], respectively) and statistically different (p < 0.0001). These events tended to occur earlier for desloratadine than levocetirizine (50% at 7 or 14 days of observation, respectively; p = 0.6487), but the cumulative time to event differed, with more events observed for levocetirizine than expected (p < 0.0001; 46 vs 28.09). The final estimates of risk were the sex-adjusted ORs for each prescribing indication category: allergic rhinitis with asthma/wheezing (3.51; 95% CI 0.71, 17.43; n = 3357), allergic rhinitis without asthma/wheezing (6.75; 95% CI 2.37, 19.22; n = 12 627) and ‘other’ (3.11; 95% CI 0.86, 11.31; n = 6725). Discussion: Although the reporting rates of drowsiness and sedation are low for both drugs, patients prescribed levocetirizine are more likely to experience drowsiness and sedation in the first month of observation (after starting treatment) than patients prescribed desloratadine. For patients with allergic rhinitis without asthma/wheezing, the sex-adjusted odds of drowsiness/sedation were over six times greater in patients using levocetirizine than desloratadine in the first month of observation, with the OR being statistically significant. For the other two indication categories, allergic rhinitis with asthma/wheezing and ‘other’, the OR was not statistically significant. Conclusions: Although the risk of drowsiness/sedation is low, conditions such as allergic rhinitis are common, which makes any impact on patient cognitive function important. Doctors should be aware of this when prescribing these products to patients where daytime sedation is undesirable. However, essential components of the comparative benefit-risk evaluation of these two products include assessment of efficacy and patient preference (neither of which forms part of this study). [ABSTRACT FROM AUTHOR]

Background: The erythema multiforme (EM) spectrum of bullous eruptions (toxic epidermal necrolysis [TEN] and Stevens-Johnson syndrome [SJS]) are rare and serious skin reactions that have been reported for cyclo-oxygenase (COX)-2 selective inhibitors. Our objectives were to identify and describe cases of serious skin reactions reported during postmarketing studies of COX-2 selective inhibitors.Methods: A retrospective review of information from reports of serious skin reactions reported during prescription-event monitoring (PEM) studies of rofecoxib, celecoxib, etoricoxib and valdecoxib conducted in England since 1999. Exposure data were derived from dispensed prescriptions written by primary care physicians for each study drug. Outcome data were derived from questionnaires posted to prescribers at least 9 months after the date of the first prescription for each patient (valdecoxib data collection ongoing at the time of this study). Reports of EM, exfoliative dermatitis, SJS, TEN and symptoms associated with EM (EM syndrome) were identified from the PEM database. Additional data on diagnosis, relevant risk factors and management were requested for each case from the prescriber. A causality assessment was undertaken by a Drug Safety Research Unit research fellow and referred for expert review to a consultant dermatologist.Results: Nine cases of serious skin reactions and two cases of symptoms associated with EM (EM syndrome) were identified. No reports of TEN were recorded. Six skin reaction questionnaires were returned. Of the nine cases of serious skin reactions, four cases (all SJS; one for each COX-2 selective inhibitor studied) were assessed as possibly related to use of the study drug (for combined cohorts: incidence risk 0.008%, 4 of 52,644 patients; rate 0.019 per 1000 patient-months of treatment). These four cases (two male, two female; age range 54-64 years) occurred within 2 weeks of starting treatment; the patient prescribed rofecoxib had reported risk factors (history of allergy, adverse reaction [asthma] to ibuprofen). The two cases from the EM syndrome search (one female, 35 years; one male, 80 years) occurred within 2 weeks of starting treatment; both were assessed as possibly related to use of celecoxib but considered suggestive of angio-oedema/urticaria and hypersensitivity reactions.Conclusions: This case series provides useful and complementary information to other published studies about serious skin reactions reported during treatment with COX-2 selective inhibitors. The crude incidence of cases of SJS possibly related to the use of a COX-2 selective inhibitor in this case series is very low (0.008% for all four cohorts combined). Prescribers and patients should be aware of the severe and life-threatening risk of EM potentially associated with NSAIDs, including COX-2 selective inhibitors. [ABSTRACT FROM AUTHOR]

The purpose of this review was to estimate the extent of under-reporting of adverse drug reactions (ADRs) to spontaneous reporting systems and to investigate whether there are differences between different types of ADRs. A systematic literature search was carried out to identify studies providing a numerical estimate of under-reporting. Studies were included regardless of the methodology used or the setting, e.g. hospital versus general practice. Estimates of under-reporting were either extracted directly from the published study or calculated from the study data. These were expressed as the percentage of ADRs detected from intensive data collection that were not reported to the relevant local, regional or national spontaneous reporting systems. The median under-reporting rate was calculated across all studies and within subcategories of studies using different methods or settings.In total, 37 studies using a wide variety of surveillance methods were identified from 12 countries. These generated 43 numerical estimates of under-reporting. The median under-reporting rate across the 37 studies was 94% (interquartile range 82--98%). There was no significant difference in the median under-reporting rates calculated for general practice and hospital-based studies. Five of the ten general practice studies provided evidence of a higher median under-reporting rate for all ADRs compared with more serious or severe ADRs (95% and 80%, respectively). In comparison, for five of the eight hospital-based studies the median under-reporting rate for more serious or severe ADRs remained high (95%). The median under-reporting rate was lower for 19 studies investigating specific serious/severe ADR-drug combinations but was still high at 85%.This systematic review provides evidence of significant and widespread under-reporting of ADRs to spontaneous reporting systems including serious or severe ADRs. Further work is required to assess the impact of under-reporting on public health decisions and the effects of initiatives to improve reporting such as internet reporting, pharmacist/nurse reporting and direct patient reporting as well as improved education and training of healthcare professionals. [ABSTRACT FROM AUTHOR]

Background: In the UK, the nitrogen bisphosphonate risedronate is licensed for the prevention and treatment of osteoporosis and corticosteroid-induced osteoporosis in postmenopausal women. It is also licensed for the treatment of Paget’s disease. During a prescription-event monitoring (PEM) study on risedronate we noted a number of ophthalmological events. Recently, case reports of ophthalmological adverse drug reactions in patients taking bisphosphonates were published in the medical literature. The aim of this study was to further evaluate the association of ophthalmological events reported in relation to risedronate treatment during a PEM study on the drug. Methods: An observational cohort study (PEM study) was conducted in England between September 2000 and June 2002. General practitioners (GPs) were asked for follow-up information on selected events. Events followed up were classified as either ‘probably’, ‘possibly’ or ‘unlikely’ to be related to risedronate, using a modified WHO classification. If insufficient information was obtained on the follow-up questionnaire, the cases were categorised as ‘unassessable’. Results: Of the total PEM study cohort of 13 643 patients, 11 156 (82%) were females and 2398 (18%) were males. We received 359 reports of ophthalmological events in 313 patients during the entire study period. Of these we followed up 178 events in 178 patients. Nineteen events in 19 patients were assessed as possibly or probably related to risedronate. The age range for these patients was 50–92 years and the time to onset ranged from 7 days to 5 months. Dry eye (six reports), sore eye (five reports) and conjunctivitis (three reports) were the most frequently reported ophthalmological events assessed as probably or possibly related to risedronate therapy. GPs also reported several other inflammatory conditions of the eye, amongst them two events each of iritis and episcleritis as well as one of keratitis. However, the information received on follow up of these events was insufficient to make causality assessments. Conclusion: Patients receiving risedronate can present with a variety of signs and symptoms affecting the eye with different degrees of severity. Patients may present after the first month of treatment. Doctors should have an increased awareness of possible ophthalmological adverse drug reactions in patients receiving this drug, which may affect the eyesight in a population at increased risk of fracture if they fall. [ABSTRACT FROM AUTHOR]

Background: The objective of this study was to assess the publicly disseminated evidence used to support decisions to withdraw medicinal products for safety reasons, and related implications for the conduct of systematic reviews of harm.Methods: Medicinal products withdrawn from the UK and US markets for safety reasons were identified from websites of the UK Medicines Control Agency (now known as the Medicines and Healthcare products Regulatory Agency) and the US FDA. Related scientific evidence was identified from communications made to the public and healthcare professionals at the time of each product withdrawal. Evidence for each product withdrawal decision was classified according to study design and outcome.Results: Eleven products were withdrawn during 1999-2001. Randomised trial evidence was cited for two products (18%) and comparative observational studies for two products (18%). Evidence from spontaneous reports supported the withdrawal of eight products (73%), with four products (36%) apparently withdrawn on the basis of spontaneous reports alone. Only two products (18%) were withdrawn on evidence for a patient relevant outcome from comparative studies.Conclusions: It is rare that evidence other than spontaneous reports is cited in support of drug withdrawals. The serious implications of product withdrawal mandate the elevation of the level of evidence that supports such public health decisions. Once suspicions of important safety hazards have emerged, prospective studies may be unfeasible and may be seen as unethical. Prospective studies can strengthen the evidence base and should be planned to commence when every drug is first marketed. Systematic reviews are unlikely to elicit evidence of harm associated with a drug unless they include spontaneous reports and surrogate outcomes. [ABSTRACT FROM AUTHOR]

Risedronate sodium is indicated in postmenopausal women for the prevention and treatment of osteoporosis and for the treatment of Paget’s disease. Our aim was to evaluate the safety of risedronate in a large cohort of patients prescribed risedronate by general practitioners (GPs) in England, soon after it was marketed. An observational cohort study was conducted using the technique of prescription-event monitoring (PEM). Exposure data were obtained from dispensed National Health Service prescriptions issued between September 2000 and June 2002. Outcome data were collected by sending questionnaires to prescribing GPs requesting them to report any events that had occurred since starting risedronate, demographic details, indication, start and stop dates, reasons for stopping, suspected adverse drug reactions (ADRs) and causes of death. Event rates calculated as incidence densities (IDs) separately, for Paget’s disease group and all other patients (osteoporosis group) were ranked and the difference between IDs in month 1 and months 2–6 calculated. The osteoporosis cohort comprised 13,180 patients (10,934 [83.0%] female); median ages for female and male patients were 73 and 69 years, respectively. The most frequently reported event in the first month of treatment was dyspepsia, being also amongst the most frequently reported reasons for stopping risedronate and suspected ADR. Adverse events assessed as possibly or probably related to risedronate included, six of facial edema and one each of Stevens-Johnson syndrome, swollen tongue, palpitation and episcleritis. Risedronate was fairly well tolerated. Adverse events affecting skin, eye, cardiovascular and immunological systems were identified. Prescribing doctors should be aware of these and monitor their patients accordingly. [ABSTRACT FROM AUTHOR]

Background and Objectives: Rofecoxib, a selective cyclo-oxygenase (COX)-2 inhibitor, was a widely marketed drug that was used for relief of pain and inflammation in arthritic conditions. It was withdrawn from the market worldwide in September 2004 because of an increased risk of cardiovascular events. Celecoxib, which belongs to the same class of drugs, is now under scrutiny for the risk of similar events. The objective of our study was to compare the incidence of gastrointestinal (GI) [symptomatic and complicated upper GI] events and thromboembolic (cardiovascular, cerebrovascular and peripheral venous) events reported for patients prescribed rofecoxib or celecoxib in primary care.Methods: A retrospective analysis of selected events was conducted using data collected from previously conducted prescription-event monitoring (PEM) studies for rofecoxib and celecoxib. PEM is an observational cohort technique. Exposure data were derived from dispensed prescriptions for rofecoxib (July-November 1999) and celecoxib (May-December 2000) that were written by primary care general practitioners in England. Outcome data were clinical events and information on potential risk factors reported on simple questionnaires (posted to prescribers approximately 9 months after the date of the first prescription). Incidence rates of the first event during treatment within each thromboembolic and GI group were calculated during the 270 days after the patient started receiving either of the drugs; crude and adjusted rate ratios (RR) were calculated for rofecoxib compared with celecoxib using Poisson regression modelling.Results: The rofecoxib and celecoxib PEM cohorts contained 15 268 and 17 458 patients, respectively. For the GI event groups, the adjusted RRs for rofecoxib compared with celecoxib were: 1.21 (95% CI 1.09, 1.36) for symptomatic upper GI events and 1.60 (95% CI 0.95, 2.70) for complicated upper GI conditions. For the thromboembolic event groups, the adjusted RRs were: 1.04 (95% CI 0.50, 2.17) for cardiovascular thromboembolic events; 1.43 (95% CI 0.86, 2.38) for cerebrovascular thromboembolic events; and 0.36 (95% CI 0.01, 1.34) for peripheral venous thromboembolic events.Conclusions: This study was a retrospective comparison of PEM studies conducted for rofecoxib and celecoxib. For symptomatic upper GI events, a 21% increase in the relative rate was found for rofecoxib users compared with celecoxib users after adjusting for identified risk factors. For complicated upper GI events, no statistically significant difference in the incidence was observed between rofecoxib and celecoxib users after adjusting for identified risk factors. For the three thromboembolic event groups, no evidence of a statistically significant difference between rofecoxib and celecoxib users was found after adjusting for identified risk factors. This study contributes to the understanding of the association between COX-2 inhibitors and thromboembolic events. However, it should be borne in mind that we had information on only a limited number of confounding variables for thromboembolic events. Further research is required to fully understand the risks and benefits of using celecoxib and other COX-2 inhibitors. Meanwhile, doctors should be cautious when prescribing these products, particularly to patients with risk factors for developing thromboembolic events. [ABSTRACT FROM AUTHOR]

Raloxifene, a selective estrogen receptor modulator (SERM) licensed for the prevention of non-traumatic vertebral fractures in postmenopausal women at increased risk of osteoporosis, was launched in the UK in August 1998. The aim of the study was to monitor the safety of raloxifene prescribed in the primary care setting in England using prescription-event monitoring (PEM). Patients were identified by means of prescription data supplied by the Prescription Pricing Authority between September 1998 and November 2000. Demographic and clinical event data were collected from questionnaires posted to primary care physicians (GPs) at least 6 months after the date of the first prescription for each patient. Information on medical events, suspected adverse drug reactions (ADRs), reasons for stopping treatment, pregnancies, and causes of death was requested. Event rates [Incidence Densities (IDs): no. first reports/1000 patient-months of treatment] were calculated. Differences between IDs for events reported in month one (ID1) and months 2-6 (ID2-6) of treatment were examined. The cohort comprised 13,987 patients [median age 62 years (IQR 55,69); 99.8% female]. The major indication was osteoporosis (40.9%, n=5725). Flushing was the event with the highest ID in month 1 (22.8), reported most frequently by GPs as an ADR to raloxifene (67/461 reports) and as the reason for stopping (700/4592 reports). Events associated with starting treatment included flushing, malaise/lassitude, headache/migraine, nausea/vomiting, sweating, cramp, pain abdomen, dizziness, diarrhea, mastalgia and vaginal hemorrhage. Less common events reported during treatment included deep vein thrombosis (n=13), pulmonary embolism (n=13), thrombophlebitis (n=31) and visual disturbance (n=29). In this study, there were 122 (0.9%) confirmed deaths, of which 32 causes of death were unknown. This study shows that raloxifene is generally well tolerated when used in general practice in England. Potential signals of unrecognised ADRs requiring further evaluation included gastrointestinal adverse symptoms and vaginal hemorrhage. There were also a small number of reports of events associated with venous thromboembolism and visual disorders that require further investigation. [ABSTRACT FROM AUTHOR]

Aims: A post-marketing surveillance study using the technique of Prescription Event Monitoring was undertaken to monitor the safety of celecoxib, a cycloxygenase (COX)-2 inhibitor, as prescribed in primary care in England. Methods: Patients were identified from dispensed British National Health Service prescription data supplied in confidence by the Prescription Pricing Authority for celecoxib between May and December 2000. Simple questionnaires were sent to the prescribing general practitioner at least 6 months after the date of the first dispensed prescription for each individual patient. Event incidence densities (IDs) [the number of 1st reports per 1000 patient-months of exposure (pme)] were calculated. ID differences for events reported in month 1 (ID1) and months 2-6 (ID2) were examined for temporal changes in event rate. Information on suspected adverse drug reactions (ADRs), reasons for stopping treatment, outcome of pregnancies and cause of death were also requested. Data were gathered on potential gastrointestinal (GI) risk factors [recent use of other non-steroidal anti- inflammatory drugs (NSAIDs), past history of upper GI disorders and concomitant gastro-irritant agents or anti-ulcer drugs]. Crude IDs per 1000 pme and ID ratios were calculated according to potential risk factors, and age (≥65 years, ≤64 years). Results: The cohort comprised of 17,458 patients [median age 62 years (IQR 51,73); 68.3% female]. The most common specified indication was osteoarthritis (28.1%, n=4905). Not effective was the event with the highest ID1 (139.9 per 1000 pme). The clinical events with the highest ID1 were dyspepsia (25.4 per 1000 pme) followed by abdominal pain (10.6). These were also given frequently as reasons for stopping (551 and 174 of 9126 reports). Of 436 events in 325 patients (1.9% of total cohort) that were reported as ADRs, the most frequent were events within the alimentary system (186 reports). Uncommon events reported during treatment (not necessarily as ADRs) included allergy (0.10%, n = 17), anaphylaxis (0.01%, n = 2), angioneurotic oedema (0.02%, n=3) and bronchospasm (0.05%, n=9). There were 103 reports of events associated with thromboembolism and 111 reports of serious GI events [90 GI bleeds (upper and lower); 21 peptic ulcers] received during treatment or within I month of stopping. A past history of dyspeptic/other upper GI conditions and use of concomitant gastro-protective drugs were each associated with a significantly increased risk of dyspepsia and abdominal pain. Conclusions: Frequently reported adverse events were those GI events commonly associated with treatment with other NSAIDS. Stratification by identified risk factors suggested that channelling of high-risk patients is likely. Serious upper and lower GI events, and thromboembolic events did occur during this study, although the incidence was low (< 1 %). Doctors should continue to prescribe NSAIDs, including COX-2-specific inhibitors, with caution. [ABSTRACT FROM AUTHOR]

Inhibitors of the cyclo-oxygenase (COX)-2 isoenzyme were developed with the expectation that their use would be accompanied by a reduction in adverse reactions thought to be mediated through COX-1 compared with conventional nonselective NSAIDs. However, the results of some clinical studies and other evidence have led to the hypothesis that use of COX-2 inhibitors may contribute to an increased risk of adverse thromboembolic (TE) events. In this review, we have evaluated the evidence from small-scale in vitro and in vivo pharmacological studies, clinical trials and large-scale pharmacoepidemiological studies and commented on the relationship between the pharmacological characteristics related to thromboembolic events and the clinical effects in large-scale clinical trials and pharmacoepidemiological studies. Overall, the pharmacological evidence suggests that a prothrombotic effect of COX-2 selective inhibitors is plausible. To date, despite the results from the Vioxx Gastrointestinal Outcome Research (VIGOR) study from which the clinical concern regarding cardiovascular TE risk arose, the published data from other randomised controlled trials (RCTs), retrospective observational studies and spontaneous reporting schemes provide a conflicting body of evidence on the TE risk with COX-2 inhibitors. Concerns that COX-2 inhibitors may be associated with prothrombotic effects remain and these need to be addressed in large scale, RCTs designed specifically to investigate the possibility of an excess of adverse cardiovascular outcomes in users of some or all selective COX-2 inhibitors, both with and without concomitant low-dose aspirin (acetylsalicylic acid). Consideration must also be given to other pathophysiological mechanisms for potential cardiovascular risk linked with inhibition of COX-2. In view of the evidence reviewed, it is recommended that selective COX-2 inhibitors should be prescribed with caution, only in patients with conditions for which these drugs have proven efficacy and with careful monitoring of outcomes and adverse events. This is particularly important in the elderly, in patients with cardiovascular/renal disease and in patients with other risk factors that might predispose them to adverse events. [ABSTRACT FROM AUTHOR]