title: Olanzapine overdose: a series of analytically confirmed cases.
abstract: To describe the spectrum of clinical effects in olanzapine overdose and investigate the factors that predict severe outcomes. We analysed olanzapine-overdose events confirmed by drug analysis. Demographic, clinical and outcome data were recorded for each presentation. The relationship between dose and therapeutic olanzapine use, and outcomes (length of hospital stay, intensive care unit admission, mechanical ventilation, Glasgow coma score <9 and delirium) were investigated. Thirty-seven olanzapine overdose admissions were included. Median age was 30 years (interquartile range: 24-40 years), 24 women and 27 taking olanzapine therapeutically. Median ingested dose was 150 mg (range: 10-1600 mg). Olanzapine overdose was characterized by tachycardia (73%), central nervous system depression (43%), miosis (39%) and delirium (54%), which were either present on admission or developed within 6 h. There was no relationship between the dose and length of hospital stay, intensive care unit admission, Glasgow coma score <9 or delirium, but there was a trend towards more severe outcomes in patients not taking olanzapine therapeutically. Patients with delirium had an increased length of hospital stay and intensive care unit admission rate (50%) and 70% of them required physical or chemical restraint. Olanzapine overdose causes a high rate of delirium and central nervous system sedation that requires significant inpatient resources. Olanzapine overdoses should be initially observed for 6 h and patients not taking olanzapine regularly may have more severe effects.
authors.affiliation: Clinical Pharmacology and Toxicology, PathWest Laboratory Medicine WA, Perth, Australia.
authors.forename: Mary
authors.initials: M
authors.lastname: Morgan
authors.forename: L Peter
authors.initials: LP
authors.lastname: Hackett
authors.forename: Geoffrey K
authors.initials: GK
authors.lastname: Isbister
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000493:pharmacokinetics / Q000506:poisoning* / Q000627:therapeutic use; D001569:Benzodiazepines / Q000493:pharmacokinetics / Q000506:poisoning / Q000627:therapeutic use; D001921:Brain / Q000187:drug effects; D002492:Central Nervous System Depressants / Q000506:poisoning; D003422:Critical Care; D003693:Delirium / Q000139:chemically induced; D004305:Dose-Response Relationship, Drug; D062787:Drug Overdose; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D015877:Miosis; D000077152:Olanzapine
chemical_list: D014150:Antipsychotic Agents; D002492:Central Nervous System Depressants; D001569:Benzodiazepines; D000077152:Olanzapine