Unexpected beneficial effects of drugs: an analysis of cases in the Dutch spontaneous reporting system.

INTRODUCTION: Drug use is inherently related to both beneficial effects on health as well as the occurrence of risks. The beneficial effects may be related to efficacy, the treatment range of a product, or even to user-friendliness of a product. However, in addition to the occurrence of adverse drug reactions, a drug can also have an unexpected beneficial effect on a patient's health, not related to the indication for which the drug was used. The aim of this article is to characterize the reports of unexpected beneficial effects of drugs in the Dutch spontaneous reporting system. METHODS: A descriptive analysis was used to gain insight in number of reports and drug classes responsible for unexpected beneficial effects of drugs. Grouping of positive side effects into classes was done by a conventional qualitative content analysis of the cases. RESULTS: Four hundred nine reports which described unexpected beneficial effects of drugs were included, which mentioned 451 associations between suspected drugs and unexpected beneficial effects. There were 147 drug classes on the 4th ATC level involved. Content analysis of the reports gave rise to 22 categories of unexpected beneficial effects of drugs, including one "other category". DISCUSSION AND CONCLUSION: The analysis showed a diverse spectrum of reported reactions and drugs with some categories of unexpected beneficial effects of drugs mentioned multiple times for certain drug classes on the 4th ATC level. Most of these findings are consistent with the existing literature and knowledge on the pharmacological mechanism of the drugs in question. Coding harmonization would make it possible to study these effects in international databases.

Metamizole (Dipyrone) as an Alternative Agent in Postoperative Analgesia in Patients with Contraindications for Nonsteroidal Anti-Inflammatory Drugs.

PURPOSE: Nonsteroidal anti-inflammatory drugs (NSAIDs) play an important role in multimodal pain management. In patients with a contraindication for NSAIDs, pain management is challenging. A recent Dutch anesthesiology guideline propagates the use of metamizole (dipyrone) in these patients. Metamizole is a controversial drug, its use being previously discouraged because of the risk for agranulocytosis. We discuss whether metamizole could be an alternative to classical NSAIDs and opioids in postoperative pain management despite this drawback. METHOD: Literature review and pharmacovigilance research based on World Health Organization adverse effect registrations. RESULTS: Metamizole causes fewer gastric and duodenal ulcers than other nonselective NSAIDs, and the risk for bleeding is limited. It is unknown whether it is safer than a nonselective NSAID combined with a proton pump inhibitor. Although the drug appears to be safe for renal function in healthy volunteers, data in high-risk patients (eg, those with heart or renal failure) are lacking. The incidence of metamizole-induced agranulocytosis is controversial, but the risk is likely to be limited with short-term postoperative use in this selected group of patients. CONCLUSION: Although firm evidence is lacking, metamizole may be safer for the upper intestinal tract and kidneys than other NSAIDs, and could alternatively be used in patients with an increased risk for stomach or renal problems. Hereby, improved postoperative pain relief can potentially be achieved. The risk for metamizole-induced agranulocytosis is judged to be acceptable.

Muscle rupture associated with statin use.

AIM: Statins are used in the treatment of hyperlipidaemia. They are among the most commonly prescribed drugs worldwide. Statins have been linked to musculoskeletal adverse drug reactions. However muscle rupture has not been discussed as an adverse drug reaction to statins so far. The aim of this article is to give an overview of cases of muscle rupture associated with the use of statins. METHOD: We analyzed the cases of muscle rupture associated with the use of statins that were collected by the Netherlands Pharmacovigilance Centre Lareb complemented with the review of cases from the EudraVigilance database. RESULTS: Fifteen cases of muscle rupture associated with statin use have been identified in the database of the Netherlands Pharmacovigilance Centre. Overall, there was a plausible temporal association of events in most cases. In addition, the EudraVigilance database contained 165 reports of muscle rupture reported in patients using statins. Muscle rupture was disproportionally associated with statin use in both databases. The reporting odds ratio was 23.4 (95% CI 11.9, 46.0) and 14.6 (95% CI 12.3, 17.2), respectively. CONCLUSION: Data from spontaneous reporting systems suggest that use of statins is associated with muscle rupture. Physicians and patients should be aware that this can occur.

The Therapeutic Potential of Essential Oils in Managing Inflammatory Skin Conditions: A Scoping Review.

Conventional therapy is commonly used for the treatment of inflammatory skin conditions, but undesirable effects, such as erythema, dryness, skin thinning, and resistance to treatment, may cause poor patient compliance. Therefore, patients may seek complementary treatment with herbal plant products including essential oils (EOs). This scoping review aims to generate a broad overview of the EOs used to treat inflammatory skin conditions, namely, acne vulgaris, dermatitis and eczema, psoriasis, and rosacea, in a clinical setting. The quality, efficacy, and safety of various EOs, as well as the way in which they are prepared, are reviewed, and the potential, as well as the limitations, of EOs for the treatment of inflammatory skin conditions are discussed. Twenty-nine eligible studies (case studies, uncontrolled clinical studies, and randomized clinical studies) on the applications of EOs for inflammatory skin conditions were retrieved from scientific electronic databases (PubMed, Embase, Scopus, and the Cochrane Library). As an initial result, tea tree (Melaleuca alternifolia) oil emerged as the most studied EO. The clinical studies with tea tree oil gel for acne treatment showed an efficacy with fewer adverse reactions compared to conventional treatments. The uncontrolled studies indicated the potential efficacy of ajwain (Trachyspermum ammi) oil, eucalyptus (Eucalyptus globulus) oil, and cedarwood (Cedrus libani) oil in the treatment of acne, but further research is required to reach conclusive evidence. The placebo-controlled studies revealed the positive effects of kanuka (Kunzea ericoides) oil and frankincense (Boswellia spp.) oil in the treatment of psoriasis and eczema. The quality verification of the EO products was inconsistent, with some studies lacking analyses and transparency. The quality limitations of some studies included a small sample size, a short duration, and the absence of a control group. This present review underscores the need for extended, well-designed clinical studies to further assess the efficacy and safety of EOs for treating inflammatory skin conditions with products of assured quality and to further elucidate the mechanisms of action involved.

An Indonesian slimming drug with undeclared ingredients causing harm.

This paper reports the presence of undeclared drugs in the herbal slimming supplement Sulami®. The four cases of the adverse drug reactions related to Sulami® were reported to the Dutch Pharmacovigilance Centre (Lareb) or the Dutch Poisons Information Centre (DPIC). The analysis of all four collected samples revealed adulteration with sibutramine and canrenone. Both drugs can cause serious adverse drug reactions. From a legal point of view, it is clear that Sulami® does not meet the legal requirement for safety. As defined in the European General Food Law Regulation, food business operators are responsible for food safety. This also applies to online store owners who sell herbal preparations. Thus, it is clear that it is forbidden to sell Sulami® on the European and Dutch market. Collaboration between involved national authorities makes it possible to identify risky products. This allows the nationally responsible regulators to take targeted action. They can call on users to report sell points what makes it possible to arrest the sellers and confiscate the dangerous products. Beyond the national, also, the European enforcement organizations should take legal measures where possible, to protect public health. The Heads of Food Safety Agencies Working Group on Food Supplements "an Initiative on European level" is a good example of efforts to improve consumer safety.

Analysis of Safety Concerns on Herbal Products with Assumed Phytoestrogenic Activity.

Phytoestrogens (PEs) are plant-based compounds that can interact with estrogen receptors and are mainly used to treat menopausal complaints. However, the safety of products with assumed phytoestrogenic activity is not fully understood. This study aimed to identify plant species with assumed phytoestrogenic activity, review existing literature on their use and safety, and critically evaluate adverse reaction (AR) reports of single-herb, multi-herb, and mixed-multiple products, as submitted to the Netherlands Pharmacovigilance Centre Lareb and to VigiBase of the World Health Organization (WHO). In the Lareb database, the most commonly reported plant species to cause ARs (total of 67 reports) were Actaea racemosa L. (black cohosh) (47.8%), Humulus lupulus L. (hops) (32.8%), and Glycine max (L.) Merr. (soybean) (22.4%). In the VigiBase database (total of 21,944 reports), the top three consisted of Glycine max (L.) Merr. (71.4%), Actaea racemosa L. (11.6%), and Vitex agnus-castus L. (chaste tree) (6.4%). In the scoping review (total of 73 articles), Actaea racemosa L. (30.1%), Glycine max (L.) Merr. (28.8%), and Trifolium pratense L. (13.7%) were the most frequently mentioned plant species. ARs were most frequently reported in the system organ classes "gastrointestinal disorders", "skin and subcutaneous tissue disorders", "reproductive system and breast disorders", and "general disorders and administration site conditions". Furthermore, from the scoping review, it appeared that the use of products with assumed phytoestrogenic activity was associated with postmenopausal bleeding. It was concluded that, while the potential benefits of products with assumed phytoestrogenic activity have been extensively pursued, the potential occurrence of ARs after using these products is less well understood. This study highlights the need for further investigation and careful monitoring of these products to better understand their effects and ensure the safety and well-being of individuals using them.

Persistent sexual dysfunction after SSRI withdrawal: a scoping review and presentation of 86 cases from the Netherlands.

BACKGROUND: Sexual dysfunction is highly prevalent worldwide. A specific form is persistent sexual dysfunction after SSRI withdrawal. We conducted a systematic literature review in order to characterize factors related to post SSRI sexual dysfunction (PSSD) and analyzed spontaneous reports of persistent sexual dysfunction reported to the Netherlands Pharmacovigilance Center Lareb. RESEARCH DESIGN AND METHODS: A systematic literature review was conducted following the PRISMA-ScR guidelines. In addition, reports of PSSD submitted to the Netherlands Pharmacovigilance Center Lareb between 1992 and 2021 were analyzed. RESULTS: A total of 237 articles were retrieved through the search and 33 articles were selected for inclusion in this review, in accordance with the inclusion criteria. Information regarding the characteristics of the condition, its clinical management, patient characteristics, and impact of PSSD is presented. A total of 86 reports of persistent sexual dysfunction were analyzed. The longest case being a patient with PSSD for 23 years. The main symptoms were: loss or decreased libido (n = 53), erectile dysfunction (n = 23) and anorgasmia (n = 5). CONCLUSIONS: PSSD impact includes sexual, psychological, and social consequences. Little is known about the mechanisms underlying PSSD and no effective treatment exists. It is necessary to increase recognition of PSSD among prescribers and improve its management at the clinical level.

Adverse Drug Reactions of Intranasal Corticosteroids in the Netherlands: An Analysis from the Netherlands Pharmacovigilance Center.

BACKGROUND: Intranasal corticosteroids are one of the cornerstone treatment options for allergic rhinitis and chronic sinusitis complaints. Safety information in the summary of product characteristics may not be representative for observations in daily clinical practice. The Netherlands Pharmacovigilance Center (Lareb) collects post-marketing safety information, using spontaneous reporting systems. OBJECTIVE: Our objective was to analyse reports of adverse drug reactions associated with intranasal corticosteroids reported in the Dutch spontaneous reporting database of the Netherlands Pharmacovigilance Center Lareb to obtain insight into real-world safety data. METHODS: We retrospectively examined all adverse drug reactions of intranasal corticosteroids reported to the Netherlands Pharmacovigilance Center Lareb, entered into the database from 1991 until 1 July, 2020. RESULTS: In total, 2263 adverse drug reactions after intranasal corticosteroid use were reported in 1258 individuals. Headache (n = 143), epistaxis (n = 124) and anosmia (n = 57) were reported most frequently. Nasal septum perforation (reporting odds ratio 463.2; 95% confidence interval: 186.7-1149.7) had the highest reporting odds ratio, followed by nasal mucosal disorder (reporting odds ratio 104.5; 95% confidence interval 36.3-301.3) and hyposmia (reporting odds ratio 90.8; 95% confidence interval 45.1-182.7). Moreover, 101 (4.5%) reports were classified as serious by Lareb, including reports of Cushing's syndrome, adrenal cortical hypofunction and growth retardation. CONCLUSIONS: Many side effects are consistent with the safety information in the summary of product characteristics of intranasal corticosteroids. Several serious (systemic) side effects are reported and it is important to realise that intranasal corticosteroids may contribute to the development. Healthcare providers and patients should be aware of the potential (individual) adverse drug reactions of intranasal corticosteroids. This information could help in discussing treatment options.

Post-Marketing Safety Profile of Vortioxetine Using a Cluster Analysis and a Disproportionality Analysis of Global Adverse Event Reports.

INTRODUCTION: Vortioxetine, a multimodal serotonergic drug, is widely used as treatment for major depressive disorder. Although on the market since late 2013, the data of the relative safety of vortioxetine, especially compared to selective serotonin reuptake inhibitors, are still scarce. OBJECTIVE: The aim of this study was to explore the adverse event reporting pattern of vortioxetine through a cluster analysis. Furthermore, to compare the adverse event reporting pattern for vortioxetine with that of the selective serotonin reuptake inhibitors. METHODS: Individual case safety reports for vortioxetine in VigiBase up to 1 November, 2019 were subjected to consensus clustering, to identify and describe natural groupings of reports based on their reported adverse events. A vigiPoint exploratory analysis compared vortioxetine to the selective serotonin reuptake inhibitors in terms of relative frequencies for a wide range of covariates, including patient sex and age, reported drugs and adverse events, and reporting country. Important differences were identified using odds ratios with adaptive statistical shrinkage. RESULTS: Thirty-six clusters containing at least five reports were identified and analysed. The two largest clusters included 48% of the vortioxetine reports and appeared to represent gastrointestinal adverse events and hypersensitivity adverse events. Other distinct clusters were related to, respectively, fatigue, aggression/suicidality, convulsion, medication errors, arthralgia/myalgia, increased weight, paraesthesia and anticholinergic effects. Some of these clusters are not labelled for vortioxetine, such as arthralgia/myalgia and paraesthesia, but are known adverse events for selective serotonin reuptake inhibitors. A vigiPoint analysis revealed a higher proportion of reports from consumers and non-health professionals for vortioxetine as well as higher relative reporting rates of gastrointestinal symptoms, pruritus and mood-related symptoms, consistent with the cluster analysis. CONCLUSIONS: A pattern of co-reported adverse events that is consistent with labelled adverse events for vortioxetine and the safety profile for selective serotonin reuptake inhibitors in general was revealed. Clusters of unlabelled adverse events were identified that reflect clinical entities that might represent signals of previously unknown adverse events. More extensive analyses of spontaneous reports may help to further understand the reporting pattern of adverse events.

Drug-Induced Stuttering: Occurrence and Possible Pathways.

Background: Stuttering is a well-known condition that affects mainly children. Often, they recover as they get older. However, a drug-induced form of stuttering may occur at any age. The aim of the present study was to detect drugs that have been associated with stuttering and discuss the mechanisms involved. Method: A descriptive study based on reports submitted to the global pharmacovigilance database VigiBase of the WHO was conducted. Results: A total of 3,385 reports of dysphemia were retrieved from VigiBase. These reports were contributed by 51 countries. Antiepileptics, antidepressants, immunosuppressants, antipsychotics, and centrally acting sympathomimetics were among the most frequently implicated drugs. Conclusion: A wide variety of drugs has been linked to the occurrence or recurrence of stuttering. Several mechanisms, such as increased dopamine levels, reduction of GABA, anticholinergic properties of drugs, or changes in serotonin levels, have been associated with the development of drug-induced stuttering. Paradoxically, agents known to reduce stuttering in some people may induce it in others.

Psychiatric adverse drug reactions in the paediatric population.

OBJECTIVE: Due to lack of information on drug use in children, many drugs are used off-label in paediatrics. Increased knowledge of adverse drug reactions (ADRs) would enable a better risk-benefit analysis. Our aim was to characterise drugs causing psychiatric ADRs in children by conducting a descriptive study based on pharmacovigilance reports. DESIGN: Reports submitted to the Netherlands Pharmacovigilance Centre Lareb from 2003 to 2016 were used to investigate drugs causing psychiatric ADRs in the Dutch paediatric population. These data were corrected for drug utilisation in order to correct the number of reports for the number of users of a drug. MAIN OUTCOME MEASURES: ORs were calculated as a measure of disproportionality for drug-ADR associations for three different age groups. Significant drug-ADR associations were checked if it was labelled in the product information. RESULTS: Lareb received 918 reports of psychiatric ADRs, which constitute 15% of the reports of ADRs in children. Drugs used for the treatment of ADHD (methylphenidate and atomoxetine) and drugs used for the treatment of asthma (montelukast and fluticasone) were the most frequently reported. However, psychiatric ADRs were also reported for less often prescribed medications such as oxybutynin and isotretinoin. CONCLUSIONS: Real-world data on psychiatric ADRs in the Dutch paediatric population show a consistent pattern with what is known from drug labels and the literature. Reports of psychiatric ADRs should be taken seriously because of the impact on medication adherence and the well-being of the child and its family.

Sex Differences in Adverse Drug Reactions of Metformin: A Longitudinal Survey Study.

INTRODUCTION: In general, women more often experience metformin-associated adverse drug reactions (ADRs) than men. OBJECTIVES: We aimed to assess whether sex differences in reported ADRs for metformin are observed at different times after initiation, and to explore their concurrence with sex differences in the dose of metformin over time. This may guide future studies in assessing the involved mechanisms of sex differences in metformin-associated ADRs and may guide sex-specific management of ADRs in clinical practice. METHODS: This study has a longitudinal design using data about patients initiating metformin collected by the Dutch National Pharmacovigilance Center Lareb through their Intensive Monitoring program. Patients were asked to complete a web-based questionnaire six times after initiation (i.e., at 2 weeks, 6 weeks and at 3, 6, 9, and 12 months). The outcome variables were the proportion of patients reporting any ADR (primary) and the dose of metformin (secondary). Sex differences in the proportions of ADRs and in the dose were tested at each assessment using Pearson Chi-Squared tests and Wilcoxon rank-sum tests, respectively. Using Bonferroni adjustment for multiple testing, a p value < 0.01 was considered statistically significant. RESULTS: The number of included patients was 1712 (40.9% women). Women reported an ADR more often than men, which was statistically significant at the assessment at 2 weeks (34% vs 25%, p < 0.001), and 6 weeks (37% vs 28%, p = 0.001) after initiation. In general, women were reported to be prescribed a lower dose than men, which became statistically significant at the 9-month assessment (p < 0.01). CONCLUSIONS: Sex differences in reported ADRs were seen in the first weeks after metformin initiation, whereas statistically significant differences in self-reported prescribed dosing were observed after several months. Patients, in particular women, might benefit from being prescribed lower metformin doses at treatment initiation.

Polymorphisms of drug-metabolizing enzymes (GST, CYP2B6 and CYP3A) affect the pharmacokinetics of thiotepa and tepa.

AIMS: Thiotepa is widely used in high-dose chemotherapy. Previous studies have shown relations between exposure and severe organ toxicity. Thiotepa is metabolized by cytochrome P450 and glutathione S-transferase enzymes. Polymorphisms of these enzymes may affect elimination of thiotepa and tepa, its main metabolite. The purpose of this study was to evaluate effects of known allelic variants in CYP2B6, CYP3A4, CYP3A5, GSTA1 and GSTP1 genes on pharmacokinetics of thiotepa and tepa. METHODS: White patients (n = 124) received a high-dose regimen consisting of cyclophosphamide, thiotepa and carboplatin as intravenous infusions. Genomic DNA was analysed using polymerase chain reaction and sequencing. Plasma concentrations of thiotepa and tepa were determined using validated GC and LC-MS/MS methods. Relations between allelic variants and elimination pharmacokinetic parameters were evaluated using nonlinear mixed effects modelling (nonmem). RESULTS: The polymorphisms CYP2B6 C1459T, CYP3A4*1B, CYP3A5*3, GSTA1 (C-69T, G-52A) and GSTP1 C341T had a significant effect on clearance of thiotepa or tepa. Although significant, most effects were generally not large. Clearance of thiotepa and tepa was predominantly affected by GSTP1 C341T polymorphism, which had a frequency of 9.3%. This polymorphism increased non-inducible thiotepa clearance by 52% [95% confidence interval (CI) 41, 64, P < 0.001] and decreased tepa clearance by 32% (95% CI 29, 35, P < 0.001) in heterozygous patients, which resulted in an increase in combined exposure to thiotepa and tepa of 45% in homozygous patients. CONCLUSIONS: This study indicates that the presently evaluated variant alleles explain only a small part of the substantial interindividual variability in thiotepa and tepa pharmacokinetics. Patients homozygous for the GSTP1 C341T allele may have enhanced exposure to thiotepa and tepa.

Pharmacokinetics of cyclophosphamide and thiotepa in a conventional fractionated high-dose regimen compared with a novel simplified unfractionated regimen.

High-dose alkylating chemotherapy with cyclophosphamide (4000 or 6000 mg/m2) and thiotepa (320 or 480 mg/m2) has commonly been administered in a fractionated regimen over 4 days. A simplified unfractionated regimen would be preferable, especially because cyclophosphamide and thiotepa have been shown to influence the metabolism of each other. However, altering a dose regimen can have a profound effect on the pharmacokinetics of the compounds involved. The aim of this study was to investigate the effect of altering the fractionated administration schedule of the CTC regimen on cyclophosphamide and thiotepa pharmacokinetics. Plasma samples were collected from 124 patients who received a fractionated tiny CTC or CTC regimen of cyclophosphamide (1000 or 1500 mg m(-2) d(-1)), thiotepa (40 or 60 mg/m2 twice daily), and carboplatin (267 or 400 mg m(-2) day(-1)) for 4 days, and 16 patients who received an unfractionated mini CTC regimen of cyclophosphamide (3000 mg/m2 at day 1), carboplatin (400 mg/m2 at days 1 and 2), and thiotepa (250 mg/m2 at day 2). Plasma concentrations of cyclophosphamide and 4-hydroxycyclophosphamide were determined using high-performance liquid chromatography coupled with tandem mass spectrometric detection; plasma concentrations of thiotepa and tepa were determined using gas chromatography. Pharmacokinetics of cyclophosphamide and thiotepa were assessed using nonlinear mixed-effect modeling. The study showed that alteration of a fractionated high-dose regimen into a simplified unfractionated regimen resulted in saturation of thiotepa elimination, with a Vmax of 212 (+/-58) micromol/h and a Km of 13.7 (+/-5.9) microM. This resulted in an increased dose-corrected exposure to thiotepa (13%) and decreased dose-corrected exposure to its metabolite tepa (21%). Elimination of cyclophosphamide was not shown to be saturable. Dose-corrected exposures to cyclophosphamide and its active metabolite 4-hydroxycyclophosphamide were comparable in both regimens. Because the simplified unfractionated mini CTC regimen was more patient-friendly and because overall dose-corrected exposures to cyclophosphamide and thiotepa were not affected to a relevant extent, our data suggest that this unfractionated regimen can be used safely in future studies.

Safety profile of non-vitamin K oral anticoagulants (NOACs) from a patient perspective: a web-based cohort event monitoring study.

Objectives: Non-vitamin K oral anticoagulants (NOACs) are a relatively new group of anticoagulants. Characteristics of adverse drug reactions (ADRs) as experienced by patients in everyday use have not yet been fully clarified. The aim was to gain insight into the safety profile of NOACs from a patient's perspective. Methods: This was a prospective, observational web-based cohort event monitoring study among first-time users of NOACs. Patients were recruited between July 2012 and April 2017. They were invited to complete four web-based questionnaires 2 weeks, 5 weeks, 3 months and 6 months after starting treatment. Information was collected about patient characteristics, drug use, and characteristics of ADRs. Results: 1748 NOAC users were included. 661 (38%) experienced at least one ADR. The reported ADRs were comparable with the information described in the Summary of Product Characteristics and generally occurred within 1 week after the start. In 59% of ADRs the patients recovered. These ADRs had no impact on the use and dosage of the NOAC in 68%. In total, 9% of the patients discontinued the NOAC because of ADRs. Conclusion: Overall NOACs were well tolerated by the participants. Most reported ADRs occurred within 1 week after the start. Patients recovered from most ADRs without changes to the use of the NOAC.

Sex Differences in Reported Adverse Drug Reactions of Selective Serotonin Reuptake Inhibitors.

INTRODUCTION: Several studies have investigated sex as a risk factor for the occurrence of adverse drug reactions (ADRs) and found that women are more likely to experience ADRs than men. OBJECTIVE: The aim of this explorative study was to investigate whether differences exist in reported ADRs of selective serotonin reuptake inhibitors (SSRIs) for men and women in the database of the Netherlands Pharmacovigilance Centre Lareb. METHODS: A ratio of reports concerning women and men, corrected for the number of users, was calculated for all the ADRs reported on SSRIs. RESULTS: We found that 16 ADRs were statistically significantly more reported in women than men, and four ADRS were reported more in men than women. CONCLUSION: ADRs more reported in women than men when using SSRIs were usually dose-related ADRs or commonly occurring ADRs. Differences in the pharmacokinetics of SSRIs between men and women may explain why these reports of dose-related ADRs when using SSRIs concern women more than men.

First experiences with a tool to measure the level of clinical information present in adverse drug reaction reports.

BACKGROUND: To make a proper causality assessment of an adverse drug reaction (ADR) report, a certain level of clinical information is necessary. A tool was developed to measure the level of clinical information present in ADR reports. The aim of this study was to test the validity and reliability of the clinical documentation tool (ClinDoc) in an international setting. METHODS: The tool was developed by a panel of pharmacovigilance experts. It includes four domains: ADR, chronology of the ADR, suspected drug and patient characteristics. The final score categorizes reports into: excellent, well, moderately or poorly documented. In two rounds, eight pharmacovigilance assessors of different countries made a total of 224 assessments using the tool, with the expert panels judgement as a standard. Sensitivity and specificity were calculated. RESULTS: The tool with four outcome-categories demonstrated low sensitivity. A lack of distinctiveness was demonstrated between the categories moderate and well. Results for the second round were re-analysed using three categories. This demonstrated a better validity. CONCLUSION: This is the first tool to give insight in the level of relevant clinical information present in ADR reports. It can be used internationally to compare reports coming from different reporting methods and different types of reporters in pharmacovigilance.

Cytochrome P450 genotype and aggressive behavior on selective serotonin reuptake inhibitors.

Letter in reply to: Eikelenboom-Schieveld SJM, Fogleman JC. Letter to the Editor. Pharmcogenomics 19(14), 1095-1096 (2018) [ 1 ]. Regarding: Ekhart, Matic M, Kant A, van Puijenbroek E, van Schaik R. CYP450 genotype and aggressive behavior on selective serotonin reuptake inhibitors. Phamacogenomics 18(7), 613-620 (2017) [ 2 ].

Simultaneous quantification of cyclophosphamide and its active metabolite 4-hydroxycyclophosphamide in human plasma by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-MS/MS).

Cyclophosphamide is a cytotoxic prodrug with a very narrow therapeutic index. To study the clinical pharmacology of cyclophosphamide in a large cohort of patients a previously published method for the simultaneous quantitative determination of cyclophosphamide and 4-hydroxycyclophosphamide in human plasma using liquid chromatography tandem mass spectrometry (LC-MS/MS) was optimized. Addition of an isotopically labelled internal standard and adaptation of the gradient resulted in a fast, robust and sensitive assay. Because 4-hydroxycyclophosphamide is not stable in plasma, the compound is derivatized with semicarbazide immediately after sample collection. Sample preparation was carried out by protein precipitation with methanol-acetonitrile (1:1, v/v), containing isotopically labelled cyclophosphamide and hexamethylphosphoramide as internal standards. The LC separation was performed on a Zorbax Extend C18 column (150 mm x 2.1 mm ID, particle size 5 microm) with 1 mM ammonium hydroxide in water-acetonitrile (90:10, v/v) as the starting gradient, at a flow-rate of 0.40 mL/min with a total run time of 6 min. The lower limit of quantification (LLQ, using a 100 microL sample volume) was 200 ng/mL and the linear dynamic range extended to 40,000 ng/mL for cyclophosphamide and 50-5000 ng/mL for 4-hydroxycyclophosphamide. Accuracies as well as precisions were lower than 20% at the LLQ concentration and lower than 15% for all other concentrations. This method has been successfully applied in our institute to support ongoing studies into the pharmacokinetics and pharmacogenetics of cyclophosphamide.