dofetilide + sotalol

Dofetilide + sotalol is a combination of two class III antiarrhythmic drugs, both of which are potassium channel blockers used to treat and maintain normal sinus rhythm in patients with atrial fibrillation and to prevent ventricular arrhythmias. Dofetilide selectively blocks the cardiac potassium channel IKr, prolonging the effective refractory period and helping terminate reentrant arrhythmias. Sotalol also blocks potassium channels but has additional non-selective beta-adrenergic blocking activity. Both agents carry a risk of QT interval prolongation and potentially life-threatening arrhythmias such as torsades de pointes, especially when used together or in patients with predisposing factors[6][7][8]. The combination is not standard clinical practice due to additive proarrhythmic risks; concurrent use is generally contraindicated except under exceptional circumstances with close monitoring[1][5].