Ischemic and Thrombotic Events Associated with Concomitant Xa-inhibiting Direct Oral Anticoagulants and Antiepileptic Drugs: Analysis of the FDA Adverse Event Reporting System (FAERS).

INTRODUCTION: Factor Xa-inhibiting direct oral anticoagulants (FXa-DOACs) undergo hepatic metabolism via cytochrome P-450 (CYP450). Concomitant use of rifampicin, an inducer of these enzymes, with FXa-DOACs, has been shown to decrease FXa-DOAC concentrations in healthy subjects. Several common antiepileptic drugs (AEDs) are known to induce CYP450 enzymes as well. However, little is known regarding the impact of this potential interaction on treatment outcomes with FXa-DOACs. METHODS: We analyzed adverse event cases submitted to the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) from January 2013 to December 2018. We compared the proportion of cases reporting thromboembolic and ischemic adverse events (TAIAEs) with the concomitant use of FXa-DOACs and enzyme-inducing AEDs to the proportion of cases with FXa-DOACs and other AEDs. RESULTS: During this period, 9693 adverse event cases reported concomitant use of FXa-DOACs and AEDs. Almost all reports (> 99%) involved the use of rivaroxaban or apixaban. Compared with other AEDs, enzyme-inducing AEDs were associated with an 86% increase in the odds of reporting TAIAEs [reporting odds ratio (ROR) 1.86, 95% confidence interval (CI) 1.61-2.15; p < 0.0001]. In secondary separate analyses of rivaroxaban and apixaban, enzyme-inducing AEDs were similarly associated with increased reporting of a TAIAE (ROR 1.79, 95% CI 1.50-2.12, and ROR 1.88, 95% CI 1.41-2.48, respectively). CONCLUSION: Using real world data, we observed an increase in the odds of reporting anticoagulation treatment failure among patients treated with FXa-DOACs and concomitant enzyme-inducing AEDs compared to those treated with other AEDs.

Clinical pharmacist led hospital-wide direct oral anticoagulant stewardship program.

INTRODUCTION: In the past decade, direct-acting oral anticoagulants (DOAC) have been introduced to medical practice for several indications, with a wide range of dosing regimens. As both over- and under-dosing might lead to life-threatening events, development of methods promoting safe and effective utilization of these agents is imperative. The Hadassah Clinical Pharmacy team initiated a hospital-wide program, for monitoring and promoting safe and effective prescription of DOAC during hospitalization. This study describes the types of drug related problems addressed and the program's performance in terms of consultation rates and physician acceptance. METHODS: Electronic medical records throughout the hospital were screened for DOAC orders. All DOAC orders were assessed by a clinical pharmacist for potentially-inappropriate prescribing. When potentially-inappropriate prescribing or a drug-related problem was identified, the clinical pharmacist provided consultation on management options. In specific cases, additional guidance was provided by coagulation and pharmacology specialists. Data on patient characteristics, clinical pharmacist consultations, and physician response was retrospectively retrieved for the first six months of 2017. Characteristics of patients with and without consultations were compared, consultations were categorized by the recommended management of the drug related problem, and physician acceptance rates were evaluated by category. RESULTS: During the evaluated period, 585 patients with DOAC orders were identified. Patients were evenly distributed by gender, and age averaged 78 years. Most patients received apixaban (75%) followed by rivaroxaban (14%) and dabigatran (11%), and most (63%) received "reduced dose" regimens. Clinical pharmacists provided 258 consultations for 210 patients, regarding anticoagulation management, such that more than one in three patients on DOAC had potentially inappropriate prescribing or drug related problems. Consultations included alerts regarding potentially inappropriate DOAC doses and recommendations to increase (29%) or decrease (5%) the dose, potentially inappropriate concomitant antiplatelet agents (20%), need for DOAC level monitoring (23%), and alerts regarding other drug related problems (23%). More than 70% of recommendations were accepted by the attending physician. CONCLUSION: Due to the complexity of DOAC management, potentially-inappropriate prescribing and drug related problems are common. Multidisciplinary collaborative projects including review and consultation by clinical pharmacists are an effective method of improving management of patients on DOAC. TRIAL REGISTRATION: Retrospectively registered at clinicaltrials.gov, NCT03527615 .