Dofetilide: a new class III antiarrhythmic agent.
Dofetilide is a relatively new class III antiarrhythmic agent that selectively blocks the rapid component of the cardiac ion channel delayed rectifier current. This results in an increase in the action potential duration and effective refractory period of the myocyte, thereby terminating reentrant tachyarrhythmias and preventing their re-induction. Oral dofetilide is effective in the conversion of atrial fibrillation and flutter to sinus rhythm and in the maintenance of sinus rhythm after conversion. It is generally well tolerated but like other antiarrhythmic agents in its class, torsades de pointes may be induced as a consequence of therapy. This risk is minimized by dosage adjustment according to creatinine clearance and QT(c) interval, by selecting patients without known risk factors for torsades and by initiating treatment in a monitored hospital setting for the first 3 days. Unlike other antiarrhythmic agents, oral dofetilide did not increase mortality in patients with a recent myocardial infarction or congestive heart failure, hence its importance as an alternative medication for the pharmacological conversion of atrial fibrillation and flutter, and maintenance of sinus rhythm after conversion in patients at high risk of sudden death.
Roukoz
Henri
H
Department of Cardiovascular Medicine/F15, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA.
Saliba
Walid
W
D000200:Action Potentials / Q000187:drug effects; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use*; D001145:Arrhythmias, Cardiac / Q000188:drug therapy*; D001281:Atrial Fibrillation / Q000188:drug therapy; D001282:Atrial Flutter / Q000188:drug therapy; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D022062:Electrophysiologic Techniques, Cardiac; D006333:Heart Failure / Q000188:drug therapy; D006801:Humans; D010627:Phenethylamines / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D013449:Sulfonamides / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use*; D013617:Tachycardia, Supraventricular / Q000188:drug therapy; D016171:Torsades de Pointes / Q000139:chemically induced; D016277:Ventricular Function, Left / Q000187:drug effects
D000889:Anti-Arrhythmia Agents; D010627:Phenethylamines; D013449:Sulfonamides; C063533:dofetilide