Dofetilide (Tikosyn) is an oral antiarrhythmic drug with Class III properties, which can cause cardiac action potential prolongation. The mechanism of action is the blockade of the cardiac ion channel that carries the rapid component of the delayed rectifier potassium current, IKr. At concentrations covering several orders of magnitude, dofetilide (Tikosyn) blocks only IKr, with no relevant block of the other repolarizing potassium currents (e.g., IKs, IK1). At clinically relevant concentrations, dofetilide (Tikosyn) has no effect on sodium channels (associated with Class I effect), adrenergic alpha-receptors, or adrenergic beta-receptors (associated with Class II effect). This causes the refractory period of atrial tissue to increase, hence its effectiveness in the treatment of atrial fibrillation and atrial flutter.
Dofetilide (Tikosyn) can also cause serious ventricular arrhythmias, primarily Torsade de Pointes (TdP), a type of ventricular tachycardia associated with QT prolongation.
ATRIAL FIBRILLATION/ATRIAL FLUTTER
Dofetilide (Tikosyn) is indicated for highly symptomatic atrial fibrillation or atrial flutter (irregular heartbeats). Dofetilide (Tikosyn) has also been shown to be effective in converting the irregular heartbeats to normal rhythm. In addition, dofetilide (Tikosyn) may help maintain the normal rhythm for a longer period of time.
There may be additional indications contained in the Policy section of this document due to evaluation of criteria highlighted in the Company’s off-label policy, and/or review of clinical guidelines issued by leading professional organizations and government entities.