Appropriateness of the Direct Oral Anticoagulants Dosing in the Middle East Gulf Region

Direct oral anticoagulants (DOACs) have proven efficacy to prevent cardioembolic strokes. Data are scarce about the appropriateness of DOAC dosing in the Middle East. We investigated the prevalence of inappropriate DOAC dosing in the region. A cross-sectional study was conducted at our hospital between April 2015 and February 2019 of patients receiving 1 of the 3 available DOACs. Patients with incomplete data sets, those prescribed DOACs for indications other than atrial fibrillation, on DOACs for <30 days, and dialysis patients were excluded. A total of 608 met the inclusion criteria. The mean age was 65.2 ± 13.9 years, and most were men (58.6%). The mean CHA2DS2-VASc score was 3.8 ± 2.0. There were 346 (56.9%) on apixaban, 123 (20.2%) on dabigatran, and 139 (22.9%) on rivaroxaban. The logistic regression model showed that for the 3 agents together, age, eGFR, major bleeding history, and history of prior stroke were significantly associated with the decision to inappropriately underdose (P < 0.05). Fifteen patients had an ischemic stroke after apixaban initiation (5 underdosed and 3 overdosed). Among patients with at least one follow-up encounter, major bleeding occurred in 13 patients (11.7%) with inappropriate dosing compared with 29 patients (6.0%) with appropriate dosing (P = 0.04). Ischemic stroke occurred in 11 patients (9.9%) with inappropriate dosing compared with 15 patients (3.1%) with appropriate dosing (P < 0.01). We concluded that inappropriate DOAC underdosing is common in our region, particularly with apixaban and rivaroxaban. It is associated with increased risk of stroke and bleeding. More education targeting prescribers is needed to encourage adherence to standard dosing criteria.