Azimilide for Atrial Fibrillation: Clinical Trial Results and Implications

Azimilide dihydrochloride (or azimilide) is a class III antiarrhythmic drug currently under investigation that has been tested in atrial fibrillation in four randomized, placebo-controlled clinical trials to assess efficacy and dose range. These investigational trials showed that doses of azimilide 100 and 125 mg once daily prolonged the time to symptomatic arrhythmia recurrence in patients with a history of symptomatic atrial fibrillation, atrial flutter or both. Doses of 75 mg or less were not useful in this indication. Safety of azimilide has been examined in several different types of studies. In a large randomized clinical trial of post-infarct patients, azimilide neither increased nor decreased mortality risk. In patients with supraventricular arrhythmias, the most common adverse effects reported by patients on azimilide were approximately equal in frequency with those on placebo: headache, asthenia, infection, diarrhea and dizziness. Infrequent cases of torsade de pointes and severe neutropenia were reported in patients taking azimilide. Azimilide is an investigational antiarrhythmic drug that has shown efficacy in patients with atrial fibrillation.