Ibutilide Disease Interactions

Antiarrhythmic agents can induce severe hypotension (particularly with IV administration) or induce or worsen congestive heart failure (CHF). Patients with primary cardiomyopathy or inadequately compensated CHF are at increased risk. Antiarrhythmic agents should be administered cautiously and dosage and/or frequency of administration modified in patients with hypotension or adequately compensated CHF. Alternative therapy should be considered unless these conditions are secondary to cardiac arrhythmia.

Electrolyte imbalance can alter the therapeutic effectiveness of antiarrhythmic agents. Hypokalemia and hypomagnesemia can reduce the effectiveness of antiarrhythmic agents. In some cases, these disorders can exaggerate the degree of QTc prolongation and increase the potential for torsade de pointes. Hyperkalemia can potentiate the toxic effects of antiarrhythmic agents. Electrolyte imbalance should be corrected prior to initiating antiarrhythmic therapy. Clinical monitoring of cardiac function and electrolyte concentrations is recommended.

The safety, effectiveness, and pharmacokinetics of ibutilide fumarate have not been established in patients with hepatic or renal dysfunction. It is unlikely that dosing adjustments would be necessary in these patients. Nonetheless, it should be administered cautiously in patients with abnormal liver or renal function, and monitoring is advised.