Clozapine and myocarditis: a case series from the New Zealand Intensive Medicines Monitoring Programme.
OBJECTIVE
To examine a New Zealand case series of clozapine-associated myocarditis.


METHODS
All cases of myocarditis in the Intensive Medicines Monitoring Programme's (IMMP) clozapine database were identified and reviewed.


RESULTS
25 cases of myocarditis associated with the use of clozapine have been reported to the IMMP. The majority of cases (84%) were male and the mean age was 35.5 years. Myocarditis occurred at daily clozapine doses ranging from 12.5 mg to 500 mg. Eighty percent of the cases developed within 1 month of starting the medicine, although in three cases the onset was more than a year after commencing clozapine. Of the 25 cases, 2 patients died.


CONCLUSIONS
This New Zealand case series of clozapine-associated myocarditis is similar to a recent Australian case series. Clozapine-associated myocarditis most often occurs within 1-2 months of starting clozapine, but it may develop at any time while on the medicine, and can occur even at very low doses. A data-linkage study using national morbidity and mortality datasets could estimate the incidence of clozapine-associated myocarditis in New Zealand.
Intensive Medicines Monitoring Programme, Department of Preventive and Social Medicine, University of Otago, PO Box 913, Dunedin, New Zealand.
Geraldine R
GR
Hill
Mira
M
Harrison-Woolrych
D000293:Adolescent; D000328:Adult; D016907:Adverse Drug Reaction Reporting Systems; D000368:Aged; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000009:adverse effects*; D003024:Clozapine / Q000008:administration & dosage / Q000009:adverse effects*; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009205:Myocarditis / Q000139:chemically induced* / Q000453:epidemiology* / Q000628:therapy; D009520:New Zealand / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate
D014150:Antipsychotic Agents; D003024:Clozapine