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Background Discrepancies in medication lists are common and can contribute to drug-related problems. This study was performed before the implementation of the National Medication List in Sweden, an intervention expected to improve the accuracy of medication lists. Aim The aim of the study was to examine the number and type of discrepancies in the medication list from pharmacies in Sweden. The secondary aim was to describe the information sources Swedish patients used as their medication lists and how confident they were with the information. Method Structured interviews were conducted with patients at 13 community pharmacies in Sweden during the period October 5, 2020, to April 16, 2021. The printed medication list was reviewed together with the patient to identify any discrepancies and missing information. Results A total of 327 patients were included in the study (response rate 51%). The printed medication list from pharmacies was the most common information source for patients to know which medications to use. Two thirds (n = 215) of the patients had at least one discrepancy among their prescriptions and 32% (n = 106) were missing at least one prescription medication. Among all prescriptions (n = 2567) 10% (n = 264) were non-current prescriptions, 9% (n = 238) were duplicates and 3% (n = 88) had the wrong dose. The proportion of prescriptions with discrepancies differed between drug-groups. Conclusion The discrepancies described in this study can have serious consequences, and results provide a baseline for studies after the implementation of the National Medication List.

Adverse drug reactions (ADRs) for all drugs in Europe are described in the legally approved Summary of Product Characteristics (SmPC). An overview of all ADRs of the patients' drug list can support healthcare staff to link patient symptoms to possible ADRs. We review the possibilities and challenges to extract ADR information from SmPCs or American Structured Product Labels and present the development of our semi-automated procedure for extraction of ADRs from the tabulated section in the SmPCs to create a database, named Bikt, which is regularly updated and used at point of care in Sweden. The existence of five major table formats for ADRs used in the SmPCs required the development of different parsing scripts. Manual checks for correctness for all content have to be performed. The quality of extraction was investigated for all SmPCs by measuring precision, recall and F1 scores and compared with other methods published. We conclude that it is possible to semi-automatically extract ADR information from SmPCs. However, clear technical and content guidelines and standards for ADR tables and terms from drug registration authorities would lead to improved extraction and usability of ADR information at point of care.

Model-informed precision dosing (MIPD) has become synonymous with modern approaches for individualizing drug therapy, in which the characteristics of each patient are considered as opposed to applying a one-size-fits-all alternative. This review provides a brief account of the current knowledge, practices, and opinions on MIPD while defining an achievable vision for MIPD in clinical care based on available evidence. We begin with a historical perspective on variability in dose requirements and then discuss technical aspects of MIPD, including the need for clinical decision support tools, practical validation, and implementation of MIPD in health care. We also discuss novel ways to characterize patient variability beyond the common perceptions of genetic control. Finally, we address current debates on MIPD from the perspectives of the new drug development, health-care economics, and drug regulations. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 61 is January 7, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Drug-drug interactions are increasingly common, as patients are getting older and the number of drugs per patient is increasing. In this study, we investigated to which extent potential drug-drug interactions originated from single or multiple prescribers. All patients attending any of 20 primary healthcare centres were included in a retrospective observational cohort study. Data on all prescriptions to these patients, irrespectively of the prescriber, were collected for two 4-month periods. Potential drug interactions were identified using the drug-drug interaction database SFINX. Interactions were classified with respect to the workplace of the prescriber, and the prevalence of interactions according to origin was analysed. We found that the drug interactions were significantly more common when the drugs were prescribed from different healthcare centres, compared with drugs prescribed from the patients' primary healthcare centre only. One explanation for this increased risk of drug interactions could be that the prescribers at different primary healthcare centres do not share the same information concerning the total medication list of the patient.

PurposeTo describe the occurrence of potential drug-drug interactions (DDIs) in prescribed drugs, dispensed to pediatric outpatients in Sweden.MethodsA cross sectional study was conducted based on data from a national register of prescribed drugs, dispensed at pharmacies, to children 0-17 years old. The study period was January 1 to April 30, 2010. Drug dispensing data was linked to the DDI database SFINX. Prevalence and frequencies of potential interactions were investigated, and drugs commonly involved in interactions were identified. The study focused on clinically relevant potential interactions, class D (should be avoided), and class C (can be handled, e.g. by dose adjustment).ResultsIn the Swedish pediatric population, 0 to 17 years of age, 12% (n = 231 078) of children had at least two dispensed drugs. In this group of patients, 0.14% had potential D-interactions and 1,3% had potential C-interactions. The number of D- and C-interactions that may lead to reduced effects were 181 (52%), and 1224 (32%) respectively. The ten most frequent drugs were involved in 78% and 65% of all potential D-, and C-interactions respectively. Furthermore, 80%, and 58% of the D-, and C-interactions respectively occurred in patients aged 12 to 17.ConclusionsWe identified a limited number of drugs that were represented in the majority of potential interactions. Interactions that can lead to a reduced treatment effect constituted approximately half of D-interactions, and a third of C-interactions. The frequency of potential interactions was higher in older children. The results may contribute to increased prescriber awareness of important potential drug interactions among pediatric outpatients.

AIMS Relevant and easily accessible drug information at point-of-care is essential for physicians' decision making when prescribing. However, the information available by using Clinical Decision Support Systems (CDSSs) often does not meet physicians' requirements. The Summary of Product Characteristics (SmPC) is statutory information about drugs. However, the current structure, content and format of SmPCs make it difficult to incorporate them into CDSSs and link them to relevant patient information from the Electronic Health Records. The aim of the study was to evaluate the perceived needs for drug information among physicians in Sweden. METHODS We recruited three focus group discussions with 18 physicians covering different specialities. The information from the groups was combined with a questionnaire administered at the beginning of the group discussions. RESULTS Physicians reported their needs for knowledge databases at the point of drug prescribing. This included more consistent information about existing and new drugs. They also wished to receive automatically generated alerts for severe drug-drug interactions and adverse effects, and to have functions for calculating glomerular filtration rate to enable appropriate dose adjustments to be made for elderly patients and those with impaired renal function. Additionally, features enhancing electronic communication with colleagues and making drug information more searchable were suggested. CONCLUSIONS The results from the current study showed the need for knowledge databases which provide consistent information about new and existing drugs. Most of the required information from physicians appeared to be possible to transfer from current SmPCs to CDSSs. However, inconsistencies in the SmPC information have to be reduced to enhance their utility.

Background Drug-related problems cause suffering for patients and substantial costs. Multi-dose drug dispensing is a service in which patients receive their medication packed in bags with one unit for each dose occasion. The electronic expert support system (EES) is a clinical decision support system that provides alerts if potential drug-related problems are detected among a patients’ current prescriptions, including drug–drug interactions, therapy duplications, high doses, drug-disease interactions, drug gender warnings, and inappropriate drugs and doses for geriatric or pediatric patients. Objective The aim of the study was to explore physicians’ views on the clinical relevance of alerts provided by EES. Furthermore we investigated if physicians performed any changes in drug treatment following the alerts and if there were any differences in perceived relevance and performed changes between different types of alerts and drugs. Setting Two geriatric clinics and three primary care units in Sweden. Method Prescribed medications for patients (n = 254) with multi-dose drug dispensing were analyzed for potential drug-related problems using EES. For each alert, a physician assessed clinical relevance and indicated any intended action. A total of 15 physicians took part in the study. Changes in drug treatment following the alerts were later measured. The relationship between variables was analyzed using Chi square test. Main outcome measure Physicians’ perceived clinical relevance of each alert, and changes in drug treatment following the alerts. Results Physicians perceived 68 % (502/740) of EES alerts as clinically relevant and 11 % of all alerts were followed by a change in drug treatment. Clinical relevance and likelihood to make changes in drug treatment was related to the alert category and substances involved in the alert. Conclusion In most patients with multi-dose drug dispensing, EES detected potential drug-related problems, with the majority of the alerts regarded as clinically relevant and some followed by measurable changes in drug treatment.

Clozapine (CLZ), an atypical neuroleptic with a high risk of causing agranulocytosis, is metabolized in the liver to desmethylclozapine (DCLZ) and clozapine N-oxide (CLZ-NO). This study investigated the involvement of different CYP isoforms in the formation of these two metabolites.Human liver microsomal incubations, chemical inhibitors, specific antibodies, and different cytochrome P450 expression systems were used.Km and Vmax values determined in human liver microsomes were lower for the demethylation (61 +/- 21 microM, 159 +/- 42 pmol min(-1) mg protein(-1) mean +/- s.d.; n = 4), than for the N-oxidation of CLZ (308 +/- 1.5 microM, 456 +/- 167 pmol min(-1) mg protein(-1); n = 3). Formation of DCLZ was inhibited by fluvoxamine (53 +/- 28% at 10 microM), triacetyloleandomycin (33 +/- 15% at 10 microM), and ketoconazole (51 +/- 28% at 2 microM) and by antibodies against CYP1A2 and CYP3A4. CLZ-NO formation was inhibited by triacetyloleandomycin (34 +/- 16% at 10 microM) and ketoconazole (51 +/- 13% at 2 microM), and by antibodies against CYP3A4. There was a significant correlation between CYP3A content and DCLZ formation in microsomes from 15 human livers (r=0.67; P=0.04). A high but not significant correlation coefficient was found for CYP3A content and CLZ-NO formation (r=0.59; P=0.09). Using expression systems it was shown that CYP1A2 and CYP3A4 formed DCLZ and CLZ-NO. Km and Vmax values were lower in the CYP1A2 expression system compared to CYP3A4 for both metabolic reactions.It is concluded that CYP1A2 and CYP3A4 are involved in the demethylation of CLZ and CYP3A4 in the N-oxidation of CLZ. Close monitoring of CLZ plasma levels is recommended in patients treated at the same time with other drugs affecting these two enzymes.

PurposeTo investigate the extent to which clinicians avoid well-established drug-drug interactions that cause statin-induced myopathy. We hypothesised that clinicians would avoid combining erythromycin or verapamil/diltiazem respectively with atorvastatin or simvastatin. In patients with statin-fibrate combination therapy, we hypothesised that gemfibrozil was avoided to the preference of bezafibrate or fenofibrate. When combined with verapamil/diltiazem or fibrates, we hypothesized that the dispensed doses of atorvastatin/simvastatin would be decreased.MethodsCross-sectional analysis of nationwide dispensing data. Odds ratios of interacting erythromycin, verapamil/diltiazem versus respective prevalence of comparator drugs doxycycline, amlodipine/felodipine in patients co-dispensed interacting statins simvastatin/atorvastatin versus patients unexposed (pravastatin/fluvastatin/rosuvastatin) was calculated. For fibrates, OR of gemfibrozil versus fenofibrate/bezafibrate in patients co-dispensed any statin was assessed.ResultsOR of interacting erythromycin versus comparator doxycycline did not differ between patients on interacting and comparator statins either in patients dispensed high or low statin doses (adjusted OR 0.87; 95% CI 0.60-1.25 and 0.92; 95% CI 0.69-1.23). Interacting statins were less common among patients dispensed verapamil/diltiazem as compared to patients on amlodipine/felodipine (OR high dose 0.62; CI 0.56-0.68 and low dose 0.63; CI 0.58-0.68). Patients on any statin were to a lesser extent dispensed gemfibrozil compared to patients not dispensed a statin (OR high dose 0.65; CI 0.55-0.76 and low dose 0.70; CI 0.63-0.78). Mean DDD (SD) for any statin was substantially higher in patients co-dispensed gemfibrozil 178 (149) compared to patients on statin monotherapy 127 (93), (pConclusionsPrescribers may to some extent avoid co-prescription of statins with calcium blockers and fibrates with an increased risk of myopathy. We found no evidence for avoiding co-prescriptions of statins and antibiotics with an increased risk of statin-induced adverse drug reactions. Co-prescription of statins and gemfibrozil is paradoxically associated with a marked increased statin dose, further aggravating the risk for severe myopathy.

To investigate the impact of the integration of the drug-drug interaction database SFINX into primary health care records on the prevalence of potentially serious drug-drug interactions.The study was a controlled before-and-after study on the prevalence of potential drug-drug interactions before and after the implementation of SFINX at 15 primary healthcare centres compared with 5 centres not receiving the intervention. Data on dispensed prescriptions from health care centres were retrieved from the Swedish prescribed drug register and analysed for September-December 2006 (pre-intervention) and September-December 2007 (post-intervention). All drugs dispensed during each 4 month period were regarded as potentially interacting.Use of SFINX was associated with a 17% decrease, to 1.81 × 10(-3) from 2.15 × 10(-3) interactions per prescribed drug-drug pair, in the prevalence of potentially serious drug-drug interactions (p = 0.042), whereas no significant effect was observed in the control group. The change in prevalence of potentially serious drug-drug interactions did not differ significantly between the two study groups. The majority of drug-drug interactions identified were related to chelate formation.Prescriptions resulting in potentially serious drug-drug interactions were significantly reduced after integration of the drug-drug interaction database SFINX into electronic health records in primary care. Further studies are needed to demonstrate the effectiveness of drug-drug interaction warning systems.

Objective The aim was to develop a drug-drug interaction database (SFINX) to be integrated into decision support systems or to be used in website solutions for clinical evaluation of interactions. Methods Key elements such as substance properties and names, drug formulations, text structures and references were defined before development of the database. Standard operating procedures for literature searches, text writing rules and a classification system for clinical relevance and documentation level were determined. ATC codes, CAS numbers and country-specific codes for substances were identified and quality assured to ensure safe integration of SFINX into other data systems. Much effort was put into giving short and practical advice regarding clinically relevant drug-drug interactions. Results SFINX includes over 8,000 interaction pairs and is integrated into Swedish and Finnish computerised decision support systems. Over 31,000 physicians and pharmacists are receiving interaction alerts through SFINX. User feedback is collected for continuous improvement of the content. Conclusion SFINX is a potentially valuable tool delivering instant information on drug interactions during prescribing and dispensing.