Myocarditis During Clozapine Treatment

Cardiac side effects of psychiatric drugs

“…Although fever, tachycardia, chest pain, dyspnoea, flu-like symptoms, eosinophilia, elevated cardiac enzyme levels and ECG changes may all be present, no single finding is pathognomonic (Merrill et al, 2006). Even myocardial biopsy, the diagnostic gold standard, has limited sensitivity and specificity.…”

Clozapine-Associated Myocarditis: Case Report and Literature Review

“…[3][4][5][6][7][8][9][10] According to the manufacturer's Canadian monograph, the estimated incidence of myocarditis is 1 per 14 000 patientyears, with a mortality rate of 23%. 1 Other studies have estimated the incidence at between 0.015% and 0.188% (up to about 1 in 500), with one case series estimating the incidence to be as high as 0.7%-1.2% (up to about 1 in 100).…”

“…1 Other studies have estimated the incidence at between 0.015% and 0.188% (up to about 1 in 500), with one case series estimating the incidence to be as high as 0.7%-1.2% (up to about 1 in 100). 4,5 The postulated mechanism is immunoglobulin E-mediated hypersensitivity, as up to about two-thirds of patients present with hypereosinophilia. [3][4][5] The risk of cardiovascular toxicity is highest in, but not limited to, the first month of therapy; however, the published literature includes cases of myocarditis occurring several years after initiation of clozapine.…”

“…4,5 The postulated mechanism is immunoglobulin E-mediated hypersensitivity, as up to about two-thirds of patients present with hypereosinophilia. [3][4][5] The risk of cardiovascular toxicity is highest in, but not limited to, the first month of therapy; however, the published literature includes cases of myocarditis occurring several years after initiation of clozapine. 6 A review of 10 fatal cases of clozapine-associated myocarditis found that, compared with nonfatal cases, there was a higher incidence of obesity and longer duration of clozapine therapy (21 days versus 17 days) in fatal cases.…”

“…1 The symptoms of clozapine-associated myocarditis (or any other form of myocarditis) are often nonspecific and may include fever, lethargy, dyspnea, chest discomfort, and palpitations. [3][4][5] The diagnosis of clozapine-associated myocarditis can be challenging, as the symptoms may resemble adverse effects associated with dose titration, such as fever, tachycardia, and lethargy. Signs may include elevation of jugular venous pressure, pericardial friction rub, crackles on respiratory auscultation, and pulmonary edema evident on chest radiography.…”