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It is a major clinical and public health problem that there is no clear strategy as to how we best make use of information obtained when pregnant women take drugs. For this reason, some pregnant women are not treated as they should be and some are given drugs they should not use. We suggest a monitoring system that combines some of the available datasets in Europe. Using these sources as a starting point, one can develop a system that has sufficient power to detect even rare diseases like congenital malformations and sufficient diversity to detect several possible outcomes from spontaneous abortions to childhood disorders. We also suggest that case-crossover designs should be used in case-control monitoring systems that carry a high risk of recall bias. These considerations are based upon our results from a European Union-funded concerted action called EuroMaP (Medicine and Pregnancy). [ABSTRACT FROM AUTHOR]

Vitex agnus castus L. (VAC) [Verbenaceae] is a deciduous shrub that is native to Mediterranean Europe and Central Asia. Traditionally, VAC fruit extract has been used in the treatment of many female conditions, including menstrual disorders (amenorrhoea, dysmenorrhoea), premenstrual syndrome (PMS), corpus luteum insufficiency, hyperprolactinaemia, infertility, acne, menopause and disrupted lactation. The German Commission E has approved the use of VAC for irregularities of the menstrual cycle, premenstrual disturbances and mastodynia. Clinical reviews are available for the efficacy of VAC in PMS, cycle disorders, hyperprolactinaemia and mastalgia, but so far no systematic review has been published on adverse events or drug interactions associated with VAC. Therefore, this review was conducted to evaluate all the available human safety data of VAC monopreparations. Literature searches were conducted in six electronic databases, in references lists of all identified papers and in departmental files. Data from spontaneous reporting schemes of the WHO and national drug safety bodies were also included. Twelve manufacturers of VAC-containing preparations and five herbalist organisations were contacted for additional information. No language restrictions were imposed. Combination preparations including VAC or homeopathic preparations of VAC were excluded. Data extraction of key data from all articles reporting adverse events or interactions was performed independently by at least two reviewers, regardless of study design. Data from clinical trials, postmarketing surveillance studies, surveys, spontaneous reporting schemes, manufacturers and herbalist organisations indicate that the adverse events following VAC treatment are mild and reversible. The most frequent adverse events are nausea, headache, gastrointestinal disturbances, menstrual disorders, acne, pruritus and erythematous rash. No drug interactions were reported. Use of VAC should be avoided during pregnancy or lactation. Theoretically, VAC might also interfere with dopaminergic antagonists. Although further rigorous studies are needed to assess the safety of VAC, the data available seem to indicate that VAC is a safe herbal medicine. [ABSTRACT FROM AUTHOR]

Patients want and need comprehensive and accurate information about their medicines so that they can participate in decisions about their healthcare. In particular, they require information about the likely risks and benefits that are associated with the different treatment options. However, to provide this information in a form that people can readily understand and use is a considerable challenge to healthcare professionals. One recent attempt to standardise the language of risk has been to produce sets of verbal descriptors that correspond to specific probability ranges, such as those outlined in the European Commission (EC) Pharmaceutical Committee guidelines in 1998 for describing the incidence of adverse effects. This paper provides an overview of a number of studies involving members of the general public, patients, and hospital doctors, that evaluated the utility of the EC guideline descriptors (very common, common, uncommon, rare, very rare). In all studies it was found that people significantly over-estimated the likelihood of adverse effects occurring, given specific verbal descriptors. This in turn resulted in significantly higher ratings of their perceived risks to health and significantly lower ratings of their likelihood of taking the medicine. Such problems of interpretation are not restricted to the EC guideline descriptors. Similar levels of misinterpretation have also been demonstrated with two other recently advocated risk scales (Calman's verbal descriptor scale and Barclay, Costigan and Davies' lottery scale). In conclusion, the challenge for risk communicators and for future research will be to produce a language of risk that is sufficiently flexible to take into account different perspectives, as well as changing circumstances and contexts of illness and its treatments. In the meantime, we urge the EC and other legislative bodies to stop recommending the use of specific verbal labels or phrases until there is a stronger evidence base to support their use. [ABSTRACT FROM AUTHOR]

Background: The collection of adverse event data is an important component of clinical trials, but it is not clear whether solicited or unsolicited collection methods are better at distinguishing drug effects from the effects of placebo. The objective of this analysis is to compare the reporting rates and the ability to detect drug-placebo differences with spontaneous versus solicited adverse event collection methods.Methods: Adverse events were collected by spontaneous (unsolicited) reporting and by structured questionnaires in three randomised, double-blind clinical trials. For both spontaneous and solicited adverse event collection methods, a drug/placebo (D/P) reporting ratio was computed by dividing the reporting rate for the experimental drug by the reporting rate for placebo for each adverse event. An index (Sp-So index) was calculated by dividing the spontaneous D/P ratio by the solicited D/P ratio. A number >1.0 indicates that the spontaneous adverse event collection method is more effective in distinguishing the drug from placebo and a number <1.0 suggests that the solicited adverse event collection method is more effective in distinguishing the drug from placebo.Results: Reporting rates were greater when events were solicited than when the spontaneous reporting approach was used. The Sp-So index was >1.0 for 22 of the 29 (75.9%) events examined, suggesting that spontaneous collection of adverse events is more effective in distinguishing drug effect from placebo than the solicited approach. However, more statistically significant differences between drug and placebo were detected by the solicited method (nine events) than the spontaneous method (five events). This is due, in part, to the fact that differences in the percentages of adverse events between drug and placebo (rather than ratios of event rates) were more often greater when the solicited approach was used.Conclusions: As expected, adverse events collected by solicitation leads to higher reporting rates. However, it is not clear that solicitation of events leads to greater ability to detect drug-placebo differences. By using a ratio to assess drug-placebo differences, spontaneous reporting provided larger drug-placebo differences more often than solicitation. [ABSTRACT FROM AUTHOR]

Nomenclature surrounding drug safety needs to be clear and unambiguous, so that patients, prescribers, manufacturers, and regulators can all understand each other. In particular, it needs to make it clear how adverse events and drug therapy are related to one another, how they are best classified, and their frequency, intensity and seriousness. In this article, we therefore discuss and define terms used in the field of drug safety, particularly terms that are sometimes misunderstood or misused, including medicinal product, pharmaceutical formulation, excipient, adverse event (or experience) and adverse drug reaction (or effect). We also discuss terms used to define the seriousness, intensity, and risk of adverse reactions, and their classification. Instead of creating definitions from scratch, as is commonly done, we have taken the novel approach of critically examining definitions that have been proposed or widely used and have formulated new or modified definitions based on a logical appraisal of their merits and demerits. We hope that these definitions will lead to discussion that will allow a corpus of satisfactory definitions to be widely agreed. [ABSTRACT FROM AUTHOR]

Herpes zoster occurs in up to 20% of people infected with varicella-zoster virus, due to reactivation of the virus from latently infected sensory ganglia. Although pain is a typical feature of acute zoster, pain persisting for more than a month after resolution of the rash is less common and is termed postherpetic neuralgia (PHN). The pain associated with PHN is neuropathic in origin and is notoriously difficult to treat. The incidence of herpes zoster and its associated complications both increase with age, so PHN should be seen more commonly in an aging population. Vaccination with live, attenuated varicella vaccine is safe and efficacious, particularly in children. It decreases the incidence of acute varicella and subsequent herpes zoster. Aciclovir is well tolerated, with renal toxicity only at high intravenous doses. Treatment of acute varicella with aciclovir attenuates acute illness but does not prevent herpes zoster. Treatment of herpes zoster with aciclovir or its derivatives minimises symptoms and may reduce the rate of PHN. Foscarnet is an alternative for an aciclovir-resistant virus but its use is limited by renal and CNS toxicity. Corticosteroids reduce acute pain in herpes zoster but do not affect the incidence of PHN. Their use in some patients may be limited by adverse effects such as gastritis and impaired glucose tolerance. Treatment of established PHN is difficult and may require a holistic approach. Tricyclic antidepressants and gabapentin are the systemic agents with the most proven benefit, although opioids such as oxycodone and NMDA receptor antagonists such as ketamine may be useful in some people. Adverse effects from tricyclic antidepressants are common but usually mild, while gabapentin is generally well tolerated. Although effective, the relatively common adverse effects of opioids and ketamine limit their usefulness in treating PHN. Topical treatment with 5% lidocaine patch or capsaicin is of benefit in some patients and is generally well tolerated. Intrathecal methyl prednisolone may be considered for intractable pain but efficacy and safety have not been confirmed. [ABSTRACT FROM AUTHOR]

The ability to identify individuals who are susceptible to adverse drug reactions (ADRs) has the potential to reduce the personal and population costs of drug-related morbidity. Some individuals may show an increased susceptibility to certain ADRs through genetic polymorphisms that alter their responses to various drugs. We wished to establish a methodology that would be acceptable to members of the general population and that would enable estimation of the risks that specific genetic factors confer on susceptibility to specific ADRs. Buccal swabs were selected as a minimally invasive method to obtain cells for DNA extraction. We wished to determine whether DNA of sufficient quantity and quality could be obtained to enable genotyping for two different polymorphic genes that code for enzymes that are widely involved in drug disposition. This article describes a small pilot study of methodology developed in the New Zealand Intensive Medicines Monitoring Programme (IMMP) to link prescription event monitoring (PEM) studies with pharmacogenetics. The methodology involves a nested case-control study design to investigate whether patients with genetic variants in P-glycoprotein (P-gp) and cytochrome P450 (CYP) 2C9 are more susceptible to psychiatric or visual disturbances following cyclo- oxygenase-2 inhibitor use (ADR signals identified in the IMMP database) than matched control patients taking the medication without experiencing any ADRs. It was concluded that the use of buccal swabs is acceptable to patients and provides DNA of sufficient quantity and quality for genotyping. Although no differences in the distribution of genotypes in the case and control populations were found in this small study, case-control studies investigating genetic risks for ADRs using drug cohorts from PEM studies are possible, and there are several areas where population-based studies of genetic risk factors for ADRs are needed. Examples are discussed where research in large populations is required urgently. These are: (i) genetic variations affecting P-gp function; (ii) variations affecting drugs metabolised by CYP2C9 and other polymorphic CYP enzymes; (iii) genetic variation in β-adrenergic receptors and adverse outcomes from β-adrenoceptor agonist therapy; and (iv) genetic variation in cardiac cell membrane potassium channels and their association with long QT syndromes and serious cardiac dysrhythmias. Such studies will help to identify factors that increase the risk of unwanted outcomes from drug therapy. They will also help to establish in what circumstances genotyping should be performed prior to commencing drug treatment and in tailoring drug treatment for individual patients. [ABSTRACT FROM AUTHOR]

It is important to manage blood glucose intensively in patients with type 2 diabetes mellitus in order to reduce the risk of long-term complications. Oral combination therapy that addresses insulin resistance and β-cell dysfunction is a proven means of improving glycaemic control when monotherapy becomes insufficiently effective. Metformin/glibenclamide (glyburide) combination tablets were developed to provide a means of applying this strategy while minimising polypharmacy. This review examines the tolerability profile of this treatment from four double-blind, randomised clinical trials in a total of 2342 type 2 diabetic patients with hyperglycaemia despite treatment with diet and exercise, a sulphonylurea or metformin. Treatment with combination tablets was associated with markedly superior blood glucose control, at lower doses of metformin and glibenclamide, compared with monotherapies. The incidence of symptoms of hypoglycaemia varied between dosages and trials, though the incidence of severe or biochemically confirmed hypoglycaemia or withdrawals from clinical trials for this reason was consistently low and comparable with glibenclamide alone. No patient required third-party assistance for hypoglycaemia. Significantly fewer diet-failed patients receiving low-dose combination tablets reported gastrointestinal adverse effects compared with metformin alone, with a comparable incidence between metformin and combination tablets in post-monotherapy studies. The incidence of other adverse events, including serious adverse events, was similar for combination tablets and monotherapies. The lower doses of metformin and glibenclamide with the combination tablet approach, and the design of the combination tablets themselves, may underlie the beneficial tolerability profile of this treatment. [ABSTRACT FROM AUTHOR]

Thrombocytopenia can have several causes, including the use of certain drugs. The mechanism behind drug-induced thrombocytopenia is either a decrease in platelet production (bone marrow toxicity) or an increased destruction (immune-mediated thrombocytopenia). In addition, pseudothrombocytopenia, an in vitro effect, has to be distinguished from true drug-induced thrombocytopenia. This article reviews literature on drug-induced immune thrombocytopenia, with the exception of thrombo-haemorrhagic disorders such as thrombotic thrombocytopenic purpura and heparin-induced thrombocytopenia and thrombosis. A literature search in PubMed combined with a check of the reference lists of all the retrieved articles resulted in 108 articles relevant to the subject. The drug classes that are most often associated with drug-induced immune thrombocytopenia are cinchona alkaloid derivatives (quinine, quinidine), sulfonamides, NSAIDs, anticonvulsants, disease modifying antirheumatic drugs and diuretics. Several other drugs are occasionally described in case reports of thrombocytopenia; an updated review of these case reports can be found on the internet. A small number of epidemiological studies, differing largely in the methodology used, describe incidences in the magnitude of 10 cases per 1 000 000 inhabitants per year. No clear risk factors could be identified from these studies. The underlying mechanism of drug-induced immune thrombocytopenia is not completely clarified, but at least three different types of antibodies appear to play a role (hapten-dependent antibodies, drug-induced, platelet-reactive auto-antibodies and drug-dependent antibodies). Targets for drug-dependent antibodies are glycoproteins on the cell membrane of the platelets, such as glycoprotein (GP) Ib/IX and GPIIb/IIIa. Diagnosis of drug-induced immune thrombocytopenia may consist of identifying clinical symptoms (bruising, petechiae, bleeding), a careful evaluation of the causal relationship of the suspected causative drug, general laboratory investigation, such as total blood count and peripheral blood smear (to rule out pseudothrombocytopenia), and platelet serology tests. The sensitivity of these tests is dependent on factors such as the concentration of the drug in the test and the potential sensitisation of the patient by metabolites instead of the parent drug. Drug-induced immune thrombocytopenia can be treated by withholding the causative drug and, in severe cases associated with bleeding, by platelet transfusion. Although drug-induced thrombocytopenia is a relatively rare adverse drug reaction, its consequences may be severe. Therefore it is important to extend our knowledge on this subject. Future research should focus on the identification of potential risk factors, as well as the exact mechanism underlying drug-induced thrombocytopenia. [ABSTRACT FROM AUTHOR]

Self medication is becoming an increasingly important area within healthcare. It moves patients towards greater independence in making decisions about management of minor illnesses, thereby promoting empowerment. Self medication also has advantages for healthcare systems as it facilitates better use of clinical skills, increases access to medication and may contribute to reducing prescribed drug costs associated with publicly funded health programmes. However, self medication is associated with risks such as misdiagnosis, use of excessive drug dosage, prolonged duration of use, drug interactions and polypharmacy. The latter may be particularly problematic in the elderly. Monitoring systems, a partnership between patients, physicians and pharmacists and the provision of education and information to all concerned on safe self medication, are proposed strategies for maximising benefit and minimising risk. [ABSTRACT FROM AUTHOR]

The problems relating to the use of medicines are manifold. They may differ in pharmacological, pathological, epidemiological and legal respects, and may have different consequences, for example, as regards scientific study, regulation or rational use. Pharmacovigilance is concerned with all such problems: adverse effects and interactions as well as problems relating to ineffectiveness, inappropriate use, counterfeiting, dependence or poisoning. Practically all medicine-related problems can be classified in one basic system, taking into account their characteristics and distinctions. This system distinguishes between appropriate and inappropriate drug use, dose-related and dose-unrelated problems, and types A (‘drug actions’), B (‘patient reactions’) and C (‘statistical’) adverse effects. This classification may serve as an educational tool and may be useful in when choosing a study method and for the design of effective strategies in pharmacovigilance. [ABSTRACT FROM AUTHOR]