Cardiovascular adverse effects of clozapine therapy

Abstract

Clozapine is an effective antipsychotic used in the treatment of drug-resistant schizophrenia. The use of clozapine may be associated with a number of adverse effects. Hematologic side effects, such as neutropenia and agranulocytosis, are most common. Cardiovascular complications are rare, though the incidence of these effects is believed to be underestimated. For this reason, clozapine can be used only if heart diseases and cardiac arrhythmias are excluded based on a comprehensive medical history, complete physical examination and electrocardiography. Myocarditis and cardiomyopathy are serious and potentially life-threatening complications resulting from clozapine therapy. Although the mechanism of these disorders is not fully understood, it is believed that they result from drug hypersensitivity caused by IgE-mediated allergic reaction type I. The symptoms are often untypical and nonspecific, resembling those of influenza. The most common include fever, dry cough, chest pains and leukocytosis. Patients should be closely monitored for resting tachycardia, especially during the first two months of treatment. Monitoring for cardiovascular adverse effects in the first months of therapy allows for a nearly detection of any irregularities and prevention of serious consequences. If myocarditis and cardiomyopathy are suspected, the treatment should be discontinued. Any electrocardiographic irregularities should be consulted with a cardiologist. If clozapine-related myocarditis or cardiomyopathy occur, reintroduction of this drug should not be considered due to the high risk of further complications.