Dofetilide

Dofetilide is a class III antiarrhythmic agent. It is marketed under the trade name Tikosyn by Pfizer, and is available in the United States in capsules containing 125, 250, and 500 µg of dofetilide. It is not available in Europe or Australia.

Due to the pro-arrhythmic potential of dofetilide, it is only available by prescription from physicians who have undergone specific training in the risks of treatment with dofetilide. In addition, it is only available by mail order or through specially trained local pharmacies.

Uses

Dofetilide is used for the maintenance of sinus rhythm in individuals prone to the occurrence of atrial fibrillation and flutter arrhythmias, and for chemical cardioversion to sinus rhythm from atrial fibrillation and flutter.

Pharmacokinetics

Dofetilide is well absorbed in its oral form, with a bioavailability of >90%.

The elimination half-life of dofetilide is roughly 10 hours; however, this varies based on many physiologic factors (most significantly creatinine clearance), and ranges from 4.8 to 13.5 hours. Due to the significant level of renal elimination (80% unchanged, 20% metabolites), the dose of dofetilide must be adjusted to prevent toxicity due to impaired renal function.