The QT prolonging effects and the risk of torsades de pointes can be increased by coadministration of dofetilide with verapamil, other drugs that also prolong the QT, or drugs that interfere with renal elimination of dofetilide (eg, cimetidine, verapamil, trimethoprim, alone or in combination with sulfamethoxazole, prochlorperazine, hydrochlorothiazide, alone or in combination with triamterene, megestrol, and ketoconazole).
