Dofetilide: a new pure class III antiarrhythmic agent.

BACKGROUND: Although there are a variety of antiarrhythmic agents used for the treatment of atrial fibrillation of flutter, each drug has drawbacks, and room exists for new pharmacologic agents. Dofetilide, a pure class III agent, has recently been approved by the Food and Drug Administration for therapy of these arrhythmias and is reviewed.
METHODS: Data for dofetilide, published in full or in abstract form, were reviewed, concentrating on the properties related to its efficacy for the therapy of supraventricular arrhythmias.
RESULTS: Results from animal and human studies indicate that dofetilide, a renally excreted drug, has pure class III properties related to blockade of the delayed rectifier potassium current. It is effective for the therapy of atrial arrhythmias, particularly atrial fibrillation and flutter, and has no demonstrable negative inotropic effect. Despite an incidence of torsades de pointes of approximately 2% in patients with impaired ventricular function, dofetilide exhibited no association with an increased mortality rate when studied in a large series of patients with a reduced ejection fraction.
CONCLUSIONS: Dofetilide's electrophysiologic and clinical profiles suggest that it will be safe and clinically useful for the termination and prevention of atrial fibrillation or flutter, even in patients with impaired ventricular function.