A double-blind comparative study of clozapine and risperidone in the management of severe chronic schizophrenia.
OBJECTIVE
This prospective, double-blind, multicenter, parallel-group study compared the efficacy and safety of therapeutic doses of clozapine and risperidone in patients with severe chronic schizophrenia and poor previous treatment response.


METHODS
Male or female patients aged 18-65 years who met DSM-IV criteria for schizophrenia and study requirements for poor previous treatment response (N=273) were randomly assigned to double-blind treatment with either clozapine or risperidone administered over 12 weeks in increasing increments. The primary efficacy measures were the magnitude of improvement in Brief Psychiatric Rating Scale (BPRS) and Clinical Global Impression (CGI) scores. Adverse events were recorded throughout the study.


RESULTS
The magnitude of improvement in mean BPRS and CGI scores from baseline to end of the study was significantly greater in the clozapine group than in the risperidone group. Statistically significant differences in favor of clozapine were also seen for most of the secondary efficacy measures (Positive and Negative Syndrome Scale, Calgary Depression Scale, Psychotic Depression Scale, and Psychotic Anxiety Scale). The adverse event profile was similar for both treatment groups, with a lower risk of extrapyramidal symptoms in the clozapine group.


CONCLUSIONS
Clozapine showed superior efficacy over risperidone in this patient population. Both treatments were equally well tolerated as demonstrated through their adverse event profiles, although as expected clozapine was associated with a lower risk of extrapyramidal symptoms than risperidone.
Azorin
J M
JM
French/Canadian Clozapine Study Group, Hôpital St. Marguerite, 270 Boulevard Ste Marguerite, 13274 Marseille Cedex 09, France. jazorin@ap-hm.fr
Spiegel
R
R
Remington
G
G
Vanelle
J M
JM
Péré
J J
JJ
Giguere
M
M
Bourdeix
I
I
D000293:Adolescent; D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001480:Basal Ganglia Diseases / Q000139:chemically induced / Q000453:epidemiology; D002908:Chronic Disease; D003024:Clozapine / Q000009:adverse effects / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012307:Risk Factors; D018967:Risperidone / Q000009:adverse effects / Q000627:therapeutic use*; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D003024:Clozapine; D018967:Risperidone