Acute stroke in patients taking an oral anticoagulant: impact of clinical pharmacist's intervention on pharmacovigilance reporting

Introduction: Ischemic or hemorrhagic stroke can occur to patients treated with oral anticoagulants (OAC), through lack of effectiveness or overdosing. Objective: To evaluate the impact of clinical pharmacist's intervention on pharmacovigilance (PV) reporting for OAC-treated patients hospitalized for stroke. Methods: Monocentric prospective study in which a clinical pharmacist's intervention was performed in a stroke unit, with a focus on patients treated by OAC prior admission. A PV report was made with all data collected for cases of stroke suspected to be related to OAC therapy. Data provided by pharmacist were compared with data initially available in the patient's electronic medical records. PV reports with pharmacist intervention were compared to those without. Results: During the study period, 48 patients were included in the study: 43 (89.6%) ischemic strokes with an embolic or unknown etiology, four hemorrhage strokes (8.33%), and one medication error (2.08%). A clinical pharmacist intervention was performed for 19 patients (39.6%) and provided significant additional data in all of them (100%). The information was related to adherence to treatment for 17 cases (89.5%), OAC's initial prescription date for 11 cases (57.9%) and identifying event(s) that could have interfered with the efficacy of the OAC in five cases (26.3%). For patients with pharmacist intervention, PV reports were significantly more informative in terms of date's introduction of anticoagulant, adherence to treatment, reference to weight change or concomitant event. Conclusions: clinical pharmacist's intervention with patients taking oral anticoagulants and hospitalized for acute stroke contributes to collect high-quality data for pharmacovigilance reporting.