Atrial Fibrillation and Injected Aripiprazole: A Case Report

Background: Aripiprazole is a widely clinically employed antipsychotic drug for a range of indications. It has unusual pharmacodynamics as a dopamine D₂ receptor partial-agonist with complex interactions with serotonin receptors and, a relatively unusual long elimination half-life. Although other atypical antipsychotics have been associated with an increased risk of atrial fibrillation, aripiprazole is considered to be relatively neutral in regard to its cardiac risk. We report a case of a 45-year-old Caucasian patient with schizoaffective disorder who developed acute atrial fibrillation (AF) several days after an intramuscular injection of a large long-acting dose of the drug after low oral doses had been well-tolerated. The patient responded to intravenous metoprolol and amiodarone and converted back to normal sinus rhythm within 24 hours, after having his oral aripiprazole dose lowered. The timing and dose-dependent effect of aripiprazole administration suggests an association between aripiprazole and the new onset of AF in this case, which calls for added clinical vigilance in patients with risk factors for stroke and in younger patients who could have predisposing factors for arrhythmias.