Standard olanzapine versus placebo and ineffective-dose olanzapine in the maintenance treatment of schizophrenia.
OBJECTIVE
Two studies compared the efficacy of standard-dose oral olanzapine (5 to 15 mg a day) with placebo and with ineffective-dose olanzapine (1 mg a day) in maintenance therapy of schizophrenia.


METHODS
The studies were 46-week double-blind extensions of multicenter studies that assessed the efficacy of olanzapine in the acute treatment of schizophrenia. Subjects were 120 adults who met DSM-III-R criteria for schizophrenia with an acute exacerbation and who had a minimum score of 24 on the Brief Psychiatric Rating Scale, who had responded to acute therapy (defined as at least a 40 percent reduction in the BPRS score from baseline or a score of 18 or less during up to six weeks of treatment), and who were outpatients at their last acute-phase visit. Relapse was defined as hospitalization for psychopathology. Relapse risk was analyzed using Kaplan-Meier survival analysis and life table analysis. Patients who relapsed were discontinued from the studies.


RESULTS
In the first study (N = 58), patients in the standard-dose olanzapine group experienced a significantly lower relapse risk (p = .002) over one year than patients treated with placebo. The estimated one-year risk of relapse with olanzapine was 28.6 percent, compared with 69.9 percent with placebo. Results were similar in the second study (N = 62); patients treated with standard-dose olanzapine had a significantly reduced risk of relapse (p = .018) over one year compared with patients treated with ineffective-dose olanzapine. The estimated one-year risks of relapse were 19.6 percent for standard-dose olanzapine and 45.5 percent for ineffective-dose olanzapine.


CONCLUSIONS
Olanzapine is superior to placebo and ineffective-dose olanzapine in the maintenance therapy of schizophrenia.
Dellva
M A
MA
Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285, USA.
Tran
P
P
Tollefson
G D
GD
Wentley
A L
AL
Beasley
C M
CM
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001569:Benzodiazepines; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D010890:Pirenzepine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010919:Placebos; D011569:Psychiatric Status Rating Scales; D012008:Recurrence; D012307:Risk Factors; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy* / Q000517:prevention & control; D012565:Schizophrenic Psychology; D016019:Survival Analysis; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D010919:Placebos; D001569:Benzodiazepines; D010890:Pirenzepine; D000077152:Olanzapine