Dofetilide: a class III anti-arrhythmic drug for the treatment of atrial fibrillation

Dofetilide is a class III anti-arrhythmic drug that has been approved for t he treatment of atrial fibrillation. Two clinical studies, which enrolled 9 96 patients, demonstrated pharmacological conversion to sinus rhythm to occ ur in 30% of patients. Following pharmacological or electrical conversion, median time to relapse exceeded one year. Two large clinical studies that e nrolled 3028 patients have been performed in high-risk patients with severe heart failure and large myocardial infarctions. The outcomes of these stud ies were neutral with respect to survival and demonstrated the safety of do fetilide. After pharmacological or electrical conversion of atrial fibrilla tion to sinus rhythm in these studies, the probability of remaining in sinu s rhythm during the following year was 75%. Dofetilide has a single signifi cant side effect: risk of developing torsade de pointes ventricular tachyca rdia. Therefore, dosage must be carefully adjusted to the length of QTc int erval, calculated creatinine clearance and the presence of heart failure or recent infarction. In addition, treatment must be initiated in hospital wi th three days of continuous telemetry. Dofetilide can be co-administered wi th digoxin and beta -blockers. Other anti-arrhythmic drugs, as well as drug s that interfere with the renal elimination or the metabolism of dofetilide , must be avoided. Dofetilide is an option when persistent atrial fibrillat ion is a clinical problem. In the setting of severe heart failure and large myocardial infarctions, only amiodarone and dofetilide have proven safety and dofetilide is a strong candidate for first choice treatment when the ai m is to achieve sinus rhythm.