Rhabdomyolysis in Clozapine Overdose

CONTEXT: Clozapine is used for decennia for the treatment of schizophrenia. Agranulocytosis, diabetic ketoacidosis, gastrointestinal hypomotility, and myocarditis are well-known adverse effects of clozapine, which are sometimes life threatening. Here we report a case of rhabdomyolysis upon an acute overdose of clozapine. CASE: A male patient, 36 years, with elevated creatinine kinase levels (9899 U/l), developed rhabdomyolysis afterafter admission to the emergency department. Approximately 2–4 h earlier he had intoxicated himself with his maintenance oral medication clozapine 125 mg, temazepam 20 mg and lorazepam 1.5 mg. Co-medications, and physical and laboratory examinations did not reveal other risk factors for rhabdomyolysis. According to the Naranjo probability scale there was a probable relation between clozapine dose and symptoms, that developed approximately 2–4 h after the auto-intoxication of 125 mg tablets. At day 5 of hospitalization, clozapine and creatinine kinase levels returned to normal and the patient was discharged with no somatic sequelae. CONCLUSIONS: Elevated creatinine kinase levels in acute clozapine intoxication may be an indicator that rhabdomyolysis may be involved.