OBJECTIVE: Clozapine, an atypical antipsychotic, has been estimated to be effective in 30% of treatment-refractory schizophrenic patients. The authors hypothesized that if a dose-response relationship was obvious for this drug, the response rate could be significantly amplified. METHOD: Following an 8-24-day dose titration phase, 29 inpatients with treatment-resistant schizophrenia diagnosed according to DSM-III-R were given a clozapine dose of approximately 400 mg/day for 4 weeks; blood samples were obtained weekly during this period. RESULTS: A receiver operator curve demonstrated that the threshold clozapine plasma concentration for therapeutic response was 350 ng/ml. Sixty-four percent of the patients with clozapine plasma concentrations greater than 350 ng/ml responded, whereas only 22% of the patients with concentrations less than 350 ng/ml responded. CONCLUSIONS: Use of clozapine blood levels as a predictor for treatment response in treatment-refractory schizophrenic patients appears worthwhile, since the measurement's sensitivity for response was 64% and the specificity for nonresponse was 78%.
OBJECTIVE:Clozapine, an atypical antipsychotic, has been estimated to be effective in 30% of treatment-refractory schizophrenicpatients. The authors hypothesized that if a dose-response relationship was obvious for this drug, the response rate could be significantly amplified. METHOD: Following an 8-24-day dose titration phase, 29 inpatients with treatment-resistant schizophrenia diagnosed according to DSM-III-R were given a clozapine dose of approximately 400 mg/day for 4 weeks; blood samples were obtained weekly during this period. RESULTS: A receiver operator curve demonstrated that the threshold clozapine plasma concentration for therapeutic response was 350 ng/ml. Sixty-four percent of the patients with clozapine plasma concentrations greater than 350 ng/ml responded, whereas only 22% of the patients with concentrations less than 350 ng/ml responded. CONCLUSIONS: Use of clozapine blood levels as a predictor for treatment response in treatment-refractory schizophrenicpatients appears worthwhile, since the measurement's sensitivity for response was 64% and the specificity for nonresponse was 78%.
Authors: D M Weiner; H Y Meltzer; I Veinbergs; E M Donohue; T A Spalding; T T Smith; N Mohell; S C Harvey; J Lameh; N Nash; K E Vanover; R Olsson; K Jayathilake; M Lee; A I Levey; U Hacksell; E S Burstein; R E Davis; M R Brann Journal: Psychopharmacology (Berl) Date: 2004-07-16 Impact factor: 4.530
Authors: Robert W Buchanan; Julie Kreyenbuhl; Deanna L Kelly; Jason M Noel; Douglas L Boggs; Bernard A Fischer; Seth Himelhoch; Beverly Fang; Eunice Peterson; Patrick R Aquino; William Keller Journal: Schizophr Bull Date: 2009-12-02 Impact factor: 9.306