title: Olanzapine plasma concentrations and clinical response in acutely ill schizophrenic patients.
abstract: Olanzapine is an atypical antipsychotic effective in the treatment of schizophrenic patients. After a 2- to 9-day placebo lead-in, 79 inpatients with schizophrenia according to DSM-III-R criteria were placed on an olanzapine dosage of 10 mg/day or 1 mg/day for up to 6 weeks. Blood samples were obtained weekly during this period. Receiver operating characteristic curve analyses of Brief Psychiatric Rating Scale (BPRS) and Positive and Negative Syndrome Scale rating scale data suggested a minimum effective therapeutic concentration of 9 ng/mL. Using an intent-to treat analysis, 45% of the patients with olanzapine plasma concentrations > or = 9.3 ng/mL responded (> or = 20% decrease in BPRS), whereas only 13% of the patients with concentrations < 9.3 ng/mL responded. Use of olanzapine plasma concentrations of > 9 ng/mL as a predictor for treatment response in acutely ill schizophrenic patients is practicable because this therapeutic marker significantly increases the likelihood of a patient responding to olanzapine.
authors.affiliation: Department of Psychiatry, College of Medicine, University of Iowa, Iowa City 52242, USA. paul-perry@uiowa.edu
authors.forename: P J
authors.initials: PJ
authors.lastname: Perry
authors.forename: T
authors.initials: T
authors.lastname: Sanger
authors.forename: C
authors.initials: C
authors.lastname: Beasley
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000097:blood* / Q000627:therapeutic use*; D001569:Benzodiazepines; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D010890:Pirenzepine / Q000031:analogs & derivatives* / Q000097:blood / Q000627:therapeutic use; D012559:Schizophrenia / Q000188:drug therapy*
chemical_list: D014150:Antipsychotic Agents; D001569:Benzodiazepines; D010890:Pirenzepine; D000077152:Olanzapine