Antiplatelet therapy guided by CYP2C19 point-of-care pharmacogenetics plus multidimensional treatment decisions.

Aim: Implementation of CYP2C19 point-of-care (POC) pharmacogenetic (PGx) testing with personalized treatment recommendations. Methods: POC CYP2C19 genotyping plus expert evaluation of risk factors for ischemic and bleeding events. Results: 167 patients underwent PGx testing, 54 (32.3%) were CYP2C19 loss of function carriers, and POC versus standard PGx analysis results for *2 and *3 variants matched in 100%. Antiplatelet therapy was adjusted in 44 patients (26.3%), but always required consideration of patient-specific factors. Conclusion: CYP2C19 POC-PGx is reliable and offers clinically relevant advantages for immediate evidence-based adaptations of antiplatelet therapy, whereas in less acute cases conventional PGx testing can also have advantages. Antiplatelet therapy has become more complex, and implementation of PGx-based personalized antiplatelet therapy requires complementary expert knowledge.

Identification of Medication Prescription Errors and Factors of Clinical Relevance in 314 Hospitalized Patients for Improved Multidimensional Clinical Decision Support Algorithms.

Potential medication errors and related adverse drug events (ADE) pose major challenges in clinical medicine. Clinical decision support systems (CDSSs) help identify preventable prescription errors leading to ADEs but are typically characterized by high sensitivity and low specificity, resulting in poor acceptance and alert-overriding. With this cross-sectional study we aimed to analyze CDSS performance, and to identify factors that may increase CDSS specificity. Clinical pharmacology services evaluated current pharmacotherapy of 314 patients during hospitalization across three units of two Swiss tertiary care hospitals. We used two CDSSs (pharmaVISTA and MediQ), primarily for the evaluation of drug-drug interactions (DDI). Additionally, we evaluated potential drug-disease, drug-age, drug-food, and drug-gene interactions. Recommendations for change of therapy were forwarded without delay to treating physicians. Among 314 patients, automated analyses by both CDSSs produced an average of 15.5 alerts per patient. In contrast, additional expert evaluation resulted in only 0.8 recommendations per patient to change pharmacotherapy. For clinical pharmacology experts, co-factors such as comorbidities and laboratory results were decisive for the classification of CDSS alerts as clinically relevant in individual patients in about 70% of all decisions. Such co-factors should therefore be used for the development of multidimensional CDSS alert algorithms with improved specificity. In combination with local expert services, this poses a promising approach to improve drug safety in clinical practice.

Rosuvastatin-induced rhabdomyolysis: case report and call for proactive multifactorial risk assessment and preventive management of statin therapy in high-risk patients.

Cholesterol-lowering statins are frequently prescribed for primary and secondary prevention of ischaemic vascular events. Whereas most patients tolerate statins without problems, statin-associated myopathy is well documented, as are several risk factors. We present a case report of an 80-90-year-old man with coronary artery disease who rapidly developed severe rhabdomyolysis during treatment with rosuvastatin while in intensive care. He had several concomitant risk factors for statin-induced myopathy including high dosage, old age, renal and hepatic impairment, and a pharmacogenetic SLCO1B1*1 a/*5 variant. Single known risk factors have a low predictive value for statin-induced myopathy and may therefore be underestimated in clinical practice. However, adverse drug reactions frequently involve the joint action of a multitude of environmental and genetic component causes, and statin-induced myopathy should be regarded as a multicausal event. We therefore advocate a proactive multifactorial risk assessment to guide and individualise statin therapy in high-risk patients.

Clinical Relevance of a 16-Gene Pharmacogenetic Panel Test for Medication Management in a Cohort of 135 Patients.

There is a growing number of evidence-based indications for pharmacogenetic (PGx) testing. We aimed to evaluate clinical relevance of a 16-gene panel test for PGx-guided pharmacotherapy. In an observational cohort study, we included subjects tested with a PGx panel for variants of ABCB1, COMT, CYP1A2, CYP2B6, CYP3A4, CYP3A5, CYP2C9, CYP2C19, CYP2D6, CYP4F2, DPYD, OPRM1, POR, SLCO1B1, TPMT and VKORC1. PGx-guided pharmacotherapy management was supported by the PGx expert system SONOGEN XP. The primary study outcome was PGx-based changes and recommendations regarding current and potential future medication. PGx-testing was triggered by specific drug-gene pairs in 102 subjects, and by screening in 33. Based on PharmGKB expert guidelines we identified at least one "actionable" variant in all 135 (100%) tested patients. Drugs that triggered PGx-testing were clopidogrel in 60, tamoxifen in 15, polypsychopharmacotherapy in 9, opioids in 7, and other in 11 patients. Among those, PGx variants resulted in clinical recommendations to change PGx-triggering drugs in 33 (32.4%), and other current pharmacotherapy in 23 (22.5%). Additional costs of panel vs. single gene tests are moderate, and the efficiency of PGx panel testing challenges traditional cost-benefit calculations for single drug-gene pairs. However, PGx-guided pharmacotherapy requires specialized expert consultations with interdisciplinary collaborations.

Implementation and management outcomes of pharmacogenetic CYP2C19 testing for clopidogrel therapy in clinical practice.

PURPOSE: The antiplatelet prodrug clopidogrel is bioactivated by the polymorphic enzyme CYP2C19. Prospective clinical studies demonstrated an association between CYP2C19 loss of function (LoF) variants and an increased risk of thrombotic events under clopidogrel, but pharmacogenetic (PGx) testing is not frequently implemented in clinical practice. We report our experience with PGx-guided clopidogrel therapy with particular regard to clinically relevant patient management changes. METHODS: We conducted an observational study analyzing patients that underwent PGx testing for clopidogrel therapy at two Swiss hospitals. Primary outcome was the proportion of patients with clinically relevant PGx-based management recommendations and their implementation. The association of recurrent ischemic events under clopidogrel with CYP2C19 LoF variants and other factors was explored in a multivariate case-control analysis. RESULTS: Among 56 patients undergoing PGx testing, 18 (32.1%) were classified as CYP2C19 intermediate or poor metabolizers. This resulted in 17 recommendations for a change of antiplatelet therapy, which were implemented in 12 patients (70.1%). In the remaining five patients, specific reasons for non-implementation could be identified. Recurrent ischemic events under clopidogrel were associated with LoF variants (OR 2.2, 95% CI 0.3-14.4) and several cardiovascular risk factors. Associations were not statistically significant in our small study, but plausible and in line with estimates from large prospective studies. CONCLUSION: PGx-guided clopidogrel therapy can identify patients with an elevated risk of ischemic events and offer evidence-based alternative treatments. Successful implementation in clinical practice requires a personalized interdisciplinary service that evaluates indications and additional risk factors, provides specific recommendations, and proactively follows their implementation.

Evaluation of Incompatible Coadministration of Continuous Intravenous Infusions in a Pediatric/Neonatal Intensive Care Unit.

OBJECTIVES: We aimed to evaluate and quantify incompatible coadministrations of continuous intravenous medication in the daily clinical practice of a PICU/NICU. METHODS: We conducted a retrospective, observational study in the setting of an 18-bed PICU/NICU. All concurrently administered continuous infusions, including blood products and parenteral nutrition, were analyzed for 2 months. Raw electronic data were retrieved and subjected to quality controls. Infusion combinations were classified as compatible, incompatible, no data, or variable according to the internal hospital charts, Trissel's database, and the Swiss summary of product characteristics. For situations with incompatible coadministrations, we assessed alternative distributions of infusions among the currently available lumen. RESULTS: Data for 100 patients were analyzed. Patients were exposed to a mean of 6.9 ± 3.6 individual continuous infusions administered through 3.8 ± 1.8 lumina. Among the 1447 coadministered continuous infusions, we detected 146 incompatible combinations (10%), resulting in 105 individually relevant incompatible situations. Furthermore, 185 combinations (13%) were not covered by internal compatibility charts, and for 207 combinations (15%) no data on compatibility were available. We found that 58% of the incompatible situations could have been avoided by a redistribution of the infusions among the available lumina. CONCLUSIONS: Most infusion combinations in the studied PICU/NICU were compatible and covered by the internal compatibility charts. However, we also identified concurrent administrations of incompatible infusions or for which compatibility data are not available. A significant reduction of coadministrations of incompatible infusions could be achieved through optimal use of available lumina.

Allergy-like immediate reactions with herbal medicines in children: A retrospective study using data from VigiBase®.

BACKGROUND: The use of herbal medicines in children and the general population is continually on the rise with an overall herbal lifetime and current use ranging between 0.8%-85.5% and 2.2%-8.9%, respectively. Although acute hypersensitivity reactions are generally considered to be rare, little knowledge exists on the frequency and type of these reactions especially in specific populations like children. OBJECTIVES: To assess the patterns of acute hypersensitivity reactions to herbal medicines reported to the WHO global individual case safety report (ICSR) database VigiBase® in children. STUDY DESIGN: From the original VigiBase® extract for the time between 1968 and 2014, we included all reports with adverse drug reactions (ADR) associated with herbal medicines in children where WHO-ART reaction terms were indicative of acute hypersensitivity reactions. RESULTS: VigiBase® contained 2646 ICSRs with 14 860 distinct adverse reactions reported in association with herbal medicine in children. Among those, 79 cases with 107 allergy-like reactions met our inclusion criteria. The most commonly reported WHO-ART terms were urticaria or rash/rash erythematous (59.8%), and allergic reaction (8.4%). The most frequently reported suspected herbal medicines were mixed herbal products (51.4%), Hedera helix (15.0%), and Echinacea purpurea (5.6%). Most frequent routes of administration were oral (75.9%), topical (8.9%), and rectal (3.8%). Over 30% of cases were reported in the age group from 7 to 12 years. The majority of reports were received from Germany (29.1%), Thailand (21.5%), and Australia (11.4%). CONCLUSION: VigiBase® contains a considerable number of acute hypersensitivity reactions in children associated with herbal medicines, including life-threatening reactions such as anaphylactic shock.

Benzodiazepine Use During Hospitalization: Automated Identification of Potential Medication Errors and Systematic Assessment of Preventable Adverse Events.

OBJECTIVE: Benzodiazepines and "Z-drug" GABA-receptor modulators (BDZ) are among the most frequently used drugs in hospitals. Adverse drug events (ADE) associated with BDZ can be the result of preventable medication errors (ME) related to dosing, drug interactions and comorbidities. The present study evaluated inpatient use of BDZ and related ME and ADE. METHODS: We conducted an observational study within a pharmacoepidemiological database derived from the clinical information system of a tertiary care hospital. We developed algorithms that identified dosing errors and interacting comedication for all administered BDZ. Associated ADE and risk factors were validated in medical records. RESULTS: Among 53,081 patients contributing 495,813 patient-days BDZ were administered to 25,626 patients (48.3%) on 115,150 patient-days (23.2%). We identified 3,372 patient-days (2.9%) with comedication that inhibits BDZ metabolism, and 1,197 (1.0%) with lorazepam administration in severe renal impairment. After validation we classified 134, 56, 12, and 3 cases involving lorazepam, zolpidem, midazolam and triazolam, respectively, as clinically relevant ME. Among those there were 23 cases with associated adverse drug events, including severe CNS-depression, falls with subsequent injuries and severe dyspnea. Causality for BDZ was formally assessed as 'possible' or 'probable' in 20 of those cases. Four cases with ME and associated severe ADE required administration of the BDZ antagonist flumazenil. CONCLUSIONS: BDZ use was remarkably high in the studied setting, frequently involved potential ME related to dosing, co-medication and comorbidities, and rarely cases with associated ADE. We propose the implementation of automated ME screening and validation for the prevention of BDZ-related ADE.

Development, implementation and outcome analysis of semi-automated alerts for metformin dose adjustment in hospitalized patients with renal impairment.

PURPOSE: Overdosing of the oral antidiabetic metformin in impaired renal function is an important contributory cause to life-threatening lactic acidosis. The presented project aimed to quantify and prevent this avoidable medication error in clinical practice. METHODS: We developed and implemented an algorithm into a hospital's clinical information system that prospectively identifies metformin prescriptions if the estimated glomerular filtration rate is below 60 mL/min. Resulting real-time electronic alerts are sent to clinical pharmacologists and pharmacists, who validate cases in electronic medical records and contact prescribing physicians with recommendations if necessary. RESULTS: The screening algorithm has been used in routine clinical practice for 3 years and generated 2145 automated alerts (about 2 per day). Validated expert recommendations regarding metformin therapy, i.e., dose reduction or stop, were issued for 381 patients (about 3 per week). Follow-up was available for 257 cases, and prescribers' compliance with recommendations was 79%. Furthermore, during 3 years, we identified eight local cases of lactic acidosis associated with metformin therapy in renal impairment that could not be prevented, e.g., because metformin overdosing had occurred before hospitalization. CONCLUSIONS: Automated sensitive screening followed by specific expert evaluation and personal recommendations can prevent metformin overdosing in renal impairment with high efficiency and efficacy. Repeated cases of metformin-associated lactic acidosis in renal impairment underline the clinical relevance of this medication error. Our locally developed and customized alert system is a successful proof of concept for a proactive clinical drug safety program that is now expanded to other clinically and economically relevant medication errors. Copyright © 2016 John Wiley & Sons, Ltd.

Drug safety of macrolide and quinolone antibiotics in a tertiary care hospital: administration of interacting co-medication and QT prolongation.

PURPOSE: Some macrolide and quinolone antibiotics (MQABs) are associated with QT prolongation and life-threatening torsade de pointes (TdP) arrhythmia. MQAB may also inhibit cytochrome P450 isoenzymes and thereby cause pharmacokinetic drug interactions (DDIs). There is limited data on the frequency and management of such risks in clinical practice. We aimed to quantify co-administration of MQAB with interacting drugs and associated adverse drug reactions. METHODS: We conducted an observational study within our pharmacoepidemiological database derived from electronic medical records of a tertiary care hospital. Among all users of MQAB associated with TdP, we determined the prevalence of additional QT-prolonging drugs and risk factors and identified contraindicated co-administrations of simvastatin, atorvastatin, or tizanidine. Electrocardiographic (ECG) monitoring and associated adverse events were validated in medical records. RESULTS: Among 3444 administered courses of clarithromycin, erythromycin, azithromycin, ciprofloxacin, levofloxacin, or moxifloxacin, there were 1332 (38.7 %) with concomitant use of additional QT-prolonging drugs. Among those, we identified seven cases of drug-related QT prolongation, but 49.1 % had no ECG monitoring. Of all MQAB users, 547 (15.9 %) had hypokalemia. Forty-four MQAB users had contraindicated co-administrations of simvastatin, atorvastatin, or tizanidine and three of those related adverse drug reactions. CONCLUSION: In the studied real-life setting, we found a considerable number of MQAB users with additional risk factors for TdP but no ECG monitoring. However, adverse drug reactions were rarely found, and costs vs. benefits of ECG monitoring have to be weighted. In contrast, avoidable risk factors and selected contraindicated pharmacokinetic interactions are clear targets for implementation as automated alerts in electronic prescribing systems.

Allergy-Like Immediate Reactions with Herbal Medicines: A Retrospective Study Using Data from VigiBase®.

INTRODUCTION: Herbal medicines are used worldwide and with an increasing popularity in Western countries. Although often perceived as 'naturally safe', herbals may cause severe adverse drug reactions (ADRs), with immediate allergic reactions being particularly life threatening. OBJECTIVES: The aim of this study was to analyse immediate allergy-like ADRs to herbals documented in VigiBase®, the WHO international pharmacovigilance database. METHODS: The documentation of all suspected ADRs in association with herbal exposure reported to VigiBase® from 1969 to August 2014 was retrieved. Among all reports in which WHO-ART reaction terms were indicative of acute allergic reactions, those classified as 'suspect' with a documented causality assessment and latency time of ≤1 day were selected. For the most frequent specific herbal-ADR combinations, the information component (IC) as a measure of disproportionality based on Bayesian statistics was calculated. RESULTS: We identified 757 reports out of 1039 ADRs. Products with mixed herbals (36.0 %) as well as those administered orally (63.2 %) were predominant. The most frequent reactions were urticaria and rash (49.2 %). Anaphylactic reactions accounted for 9.5 %. Disproportionally frequent reporting of mouth edema (IC = 1.81) and anaphylactic reactions (IC = 1.24) to Phleum pretense were noted. CONCLUSION: Our findings indicate that herbal medicines for oral use carry a risk of causing immediate allergy-like ADRs. Studies using the Vigibase® database can identify specific combinations of particular herbs and adverse reactions. Healthcare professionals and patients should be aware of these risks and report any serious adverse experiences.

Second-generation antipsychotics in a tertiary care hospital: prescribing patterns, metabolic profiles, and drug interactions.

We carried out an observational study that analyzed population characteristics, metabolic profiles, potentially interacting pharmacotherapy, and related adverse events in second-generation antipsychotics (SGAs) users of a tertiary care hospital. Within our pharmacoepidemiological database derived from electronic medical records of 82,358 hospitalizations, we identified 1136 hospitalizations contributing 9165 patient-days with exposure to SGA. Blood pressure, blood glucose, lipids, and BMI had been documented in 97.7, 75.7, 24.6, and 77.4% of hospitalizations, respectively. Among these, the prevalence of hypertension, hyperglycemia, dyslipidemia, and BMI 30 kg/m or more was 36.9, 22.6, 61.1, and 23.1%, respectively. A total of 63.4, 70.8, and 37.1% of SGA users with hyperglycemia, dyslipidemia, and hypertension, respectively, received no pharmacotherapy for these conditions. We identified 614 patient-days with SGA plus formally contraindicated comedication and another 1066 patient-days with other high-risk combinations for QTc prolongation. Among those there was one case with associated neutropenia and four cases with abnormal QTc interval. However, specific monitoring for such adverse events was not documented in 45.5% of hospitalizations with contraindicated and 89.8% with high-risk QTc-prolonging combinations. Our study identified targets for improved monitoring and management in SGA users. These may be implemented as automated alerts into electronic prescribing systems and thereby efficiently support safer pharmacotherapy in clinical practice.

Rivaroxaban postmarketing risk of liver injury.

BACKGROUND & AIMS: Rivaroxaban is an oral direct factor Xa inhibitor that has been marketed worldwide since 2008 for the primary and secondary prevention and treatment of thromboembolic disorders. Although liver injury was observed in premarketing trials of rivaroxaban, there are no published postmarketing cases of liver injury associated with rivaroxaban. METHODS: Report of 14 cases of liver injury associated with rivaroxaban, including two with liver biopsy, and search queries in three large international pharmacovigilance databases for comparable cases. RESULTS: Formal causality assessment classified rivaroxaban as the "highly probable", "probable", and "possible" cause in 4, 7, and 3 patients, respectively. Search results from three large international pharmacovigilance databases revealed a considerable number of additional hepatic adverse events where rivaroxaban was reported as a suspected cause. CONCLUSIONS: We interpret the presented information as a relevant safety signal that should be followed by pharmacoepidemiological studies in order to reliably estimate absolute and relative risks of liver injury associated with rivaroxaban in support of rational risk-benefit assessment. Meanwhile, incident symptoms and signs of liver disease in patients treated with rivaroxaban should be considered as a potential adverse drug reaction, and if no other likely cause can be identified rivaroxaban should be stopped as soon as possible.