Exacerbation of congestive heart failure secondary to moricizine

Moricizine, a recently approved phenothiazine antiarrhythmic agent, is reported to be associated with a low frequency of congestive heart failure. A 61-year-old man with a history of congestive heart failure and ischemic heart disease began taking moricizine 250 mg every 8 hours to suppress his monomorphic sustained ventricular tachycardia. After five doses he became progressively short of breath and was in pulmonary edema. Moricizine was discontinued, intravenous diuretics were administered, and the patient's clinical status stabilized. Twelve hours later, however, he developed polymorphic ventricular tachycardia and was not successfully resuscitated. Despite claims as to its safety, limited data strongly suggest that moricizine, like other antiarrhythmics, may be detrimental in patients with preexisting ventricular dysfunction, and should be prescribed with caution.