title: Serum levels of olanzapine in a non-fatal overdose.
abstract: Olanzapine is a widely used second generation antipsychotic drug. Case reports of intoxications have been published, but reports in the literature of non-fatal intoxications of olanzapine containing repeated measurements of serum levels are scarce. Therefore, this case of non-fatal olanzapine intoxication is presented, in which 19 blood samples were drawn during 2 weeks. The highest (initial) measured value was estimated at 800 pg/L. This patient ingested 550 mg of olanzapine resulting in clinical signs of intoxication, including seizures. Because the patient was found the day after the intoxication, the initial concentration had probably been higher. The pharmacokinetics of olanzapine has been described as linear and dose-proportional throughout the therapeutic dosing range. Large overdoses, however, have been described to show non-linear pharmacokinetics. In this study's series of serum concentrations, a two-phase elimination was seen, with an initial elimination half-life of about 24 h during the first 3 days, followed by a second phase with a half-life of about 2.5 days. The patient in this case recovered completely. Because the elimination time after intoxication can be considerably longer than expected, it is recommended that the patient's serum concentrations after intoxication be monitored.
authors.affiliation: Division of Clinical Pharmacology, Department of Pharmacology and Clinical Neuroscience Norrland University Hospital, Linköping University Hospital, Linköping, Sweden.
authors.forename: Roland
authors.initials: R
authors.lastname: Lennestål
authors.forename: Cay
authors.initials: C
authors.lastname: Asplund
authors.forename: Mats
authors.initials: M
authors.lastname: Nilsson
authors.forename: Hans-Ake
authors.initials: HA
authors.lastname: Lakso
authors.forename: Tom
authors.initials: T
authors.lastname: Mjörndal
authors.forename: Staffan
authors.initials: S
authors.lastname: Hägg
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000097:blood* / Q000493:pharmacokinetics / Q000506:poisoning; D001569:Benzodiazepines / Q000097:blood / Q000493:pharmacokinetics / Q000506:poisoning; D056486:Chemical and Drug Induced Liver Injury; D002851:Chromatography, High Pressure Liquid; D062787:Drug Overdose; D006207:Half-Life; D006801:Humans; D008107:Liver Diseases / Q000097:blood; D008111:Liver Function Tests; D008297:Male; D000077152:Olanzapine; D012640:Seizures / Q000139:chemically induced / Q000503:physiopathology; D013406:Suicide, Attempted
chemical_list: D014150:Antipsychotic Agents; D001569:Benzodiazepines; D000077152:Olanzapine