Ischemic Stroke Risk in Patients on Direct Oral Anticoagulants with Levetiracetam: A Pharmacovigilance Study

BackgroundLevetiracetam is widely used in post stroke epilepsy. However, it is suspected to possess P-glycoprotein induction properties and therefore a potential significant interaction with DOACs. Our aim was to search for ischemic stroke signals with levetiracetam and the DOACs. MethodsIn this retrospective, pharmacovigilance study, we used the Food and Drug Administration adverse event reporting system to identify ischemic stroke events associated with DOACs and concomitant use of levetiracetam. We evaluated disproportionate reporting by the reporting odds ratio adjusted to age and sex (adj.ROR) and the lower bound of the shrinkage 95% confidence interval ({Omega}025 > 0 is deemed significant for an interaction). ResultsWe identified 1,841 (1.5%), 3,731 (5.3%), 338 (4.9%), and 1,723 (1.3%), ischemic stroke reports with apixaban, dabigatran, edoxaban, and rivaroxaban respectively. When heparin/enoxaparin was used as the comparator the adjusted ROR of the interaction effect was 3.57 (95%CI, 2.81-4.58) between DOACs and levetiracetam. The shrinkage analysis detected an interaction between each of the DOACs and levetiracetam resulting in higher reports of ischemic stroke with the combination compared to each drug alone. The logistic model and shrinkage analysis failed to detect an interaction when queried for hemorrhagic stroke. ConclusionsWe show a strong signal for the levetiracetam interaction with apixaban, dabigatran, edoxaban, and rivaroxaban leading to a 3-5 folds increased reporting risk of ischemic stroke. Our findings suggest the need for pharmacodynamic monitoring, while concomitantly prescribing levetiracetam with the DOACs.