Myotoxicity in acute clozapine overdose.

Clozapine, an atypical antipsychotic has been associated with several side effects like sialorrhoea, sedation, tachycardia, agranulocytosis and seizure. Myotoxicity and neurotoxicity have also been reported with long-term use of clozapine. We report here a case of myotoxicity developing after acute overdose of clozapine. A 17-year-old daughter of a schizophrenic father consumed 3.9 g of clozapine in an attempted suicide. Clinical features of myotoxicity were detected on the third day, after the patient regained full consciousness. Elevated creatinine phosphokinase and muscle biopsy confirmed myositis. The patient also had tachycardia, which persisted for 10 days. This combination of myositis-induced muscle weakness and tachycardia is likely to be associated with poor outcome in clozapine overdose.