Direct Oral Anticoagulants and Concomitant Anti-seizure Medications: A Retrospective, Case-Control Study in a Real-World Setting

Abstract

Purpose: Although prescription of direct oral anticoagulants (DOACs) for epileptic patients on anti-seizure medications (ASMs) is on the increase, international guidelines pose strict restrictions because this may lead to pharmacologic interactions. However, current evidence on their clinical relevance remains scanty. This retrospective, case-control study assessed the frequency of ischemic/hemorrhagic events and epileptic seizures involving DOAC-ASM cotherapy in the real world, compared with DOAC and ASM monotherapy, in age- and gender-matched controls.

Methods: Data on patients who had been prescribed a concomitant DOAC and ASM therapy for at least 6 months were extracted from the database of the Pharmaceutical Service of the Alessandria Province (Italy). After exclusions, the case group included 124 patients, 44 on valproic acid (VPA) and 80 on levetiracetam (LEV) concomitant with a DOAC, and it was compared with the DOAC-control and ASM-control groups. The clinical and laboratory data were extracted from the electronic archives of the hospitals in the same province.

Findings: Two (1.6%) ischemic and 2 (1.6%) major hemorrhagic events were observed in the case group. Four (3.2%) ischemic and no hemorrhagic events occurred in the DOAC-control group. There were no statistically significant differences in the ischemic and hemorrhagic events between the case group (patients on concomitant LEV or VPA who were prescribed a DOAC) and the DOAC-control group, and there was no difference in the recurrence rate of epileptic seizures between the case group and the ASM-control group.

Implications: Although this study has some limits, mainly the small sample size, our findings indicate that neither LEV nor VPA concomitant treatment significantly affects the effects of DOACs in a real-world setting.

Keywords: Anti-seizure medications (ASMs); Direct oral anticoagulants (DOACs); Hemorrhagic event; Ischemic event; Levetiracetam; Valproate.