Dofetilide Disease Interactions

Dofetilide is contraindicated in patients with congenital or acquired long QT syndromes. Dofetilide should not be used in patients with a baseline QT interval of QTc >440 msec (500 msec in patients with ventricular conduction abnormalities).

Dofetilide is contraindicated in patients with severe renal impairment (calculated creatinine clearance <20 mL/min). The risk of QT interval prolongation, Torsade de Pointes, and ventricular arrhythmias is directly related to dofetilide plasma concentration. A reduced creatinine clearance will increase dofetilide plasma concentration. In patients with mild and moderate renal impairment, the risk of arrhythmias can be reduced by controlling the plasma concentration through adjustment of the initial dofetilide dose according to creatinine clearance. Patients undergoing dialysis were not included in clinical studies, and appropriate dosing recommendations for these patients are unknown. There is no information about the effectiveness of hemodialysis in removing dofetilide from plasma.

Dofetilide should be avoided in patients that experience symptoms that may be associated with altered electrolyte balance, such as excessive or prolonged diarrhea, sweating, or vomiting or loss of appetite or thirst, these conditions should immediately be reported to their health care provider.

Dofetilide has not been studied in patients with severe hepatic impairment. Dofetilide should be used with particular caution in these patients.

Serum potassium should be maintained within the normal range before dofetilide treatment is initiated and should be maintained within the normal range while the patient remains on dofetilide therapy. In clinical trials, potassium levels were generally maintained above 3.6 to 4.0 mEq/L. Exercise care when using this agent in patients with hypokalemia.