Comparison of quetiapine and risperidone in the treatment of schizophrenia: A randomized, double-blind, flexible-dose, 8-week study.
OBJECTIVE
To compare the efficacy and tolerability of quetiapine and risperidone in the treatment of schizophrenia.


METHODS
In this 8-week, double-blind, multicenter, flexible-dose study, patients with schizophrenia (DSM-IV diagnosis) were randomly assigned to quetiapine (200-800 mg/day) or risperidone (2-8 mg/day). The primary hypothesis was that quetiapine was not inferior to risperidone. The primary efficacy measure was change from baseline in Positive and Negative Syndrome Scale (PANSS) total scores; secondary outcomes included response rate (> or = 40% reduction in PANSS scores), Clinical Global Impression-Change (CGI-C), and cognitive and social functioning. Tolerability assessments included treatment-emergent adverse events and changes in weight, glucose, and prolactin. Patients were recruited from June 2001 to September 2002.


RESULTS
Patients (N = 673) were randomly assigned to quetiapine (N = 338, mean dose = 525 mg/day) or risperidone (N = 335, mean dose = 5.2 mg/day). The primary analysis demonstrated noninferiority between treatments (p < .05). Improvements with both treatments were comparable on PANSS total, negative, and general psychopathology subscales. Risperidone-treated patients had a significantly (p = .03) greater improvement in PANSS positive subscale score among all patients, but not among completers. Improvements in PANSS response rates, CGI-C, and cognitive function were similar between treatment groups. Changes in serum glucose and weight were minimal and comparable. The rate of extrapyramidal symptom (EPS)-related adverse events was significantly higher with risperidone (22%) than quetiapine (13%; p < .01). Somnolence was more common with quetiapine (26%) than risperidone (20%; p = .04). Prolactin levels increased with risperidone (+35.5 ng/mL), but decreased with quetiapine (-11.5 ng/mL; p < .001).


CONCLUSIONS
Quetiapine and risperidone had broadly comparable clinical efficacy. Both agents improved cognitive and social functioning, and neither had a clinically significant effect on weight or glucose. Somnolence was more common with quetiapine; EPS and elevated prolactin rates were significantly higher with risperidone.
Zhong
Kate X
KX
AstraZeneca Pharmaceuticals LP, Wilmington, DE 19850, USA.
Sweitzer
Dennis E
DE
Hamer
Robert M
RM
Lieberman
Jeffrey A
JA
D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001480:Basal Ganglia Diseases / Q000139:chemically induced; D003072:Cognition Disorders / Q000175:diagnosis / Q000188:drug therapy; D003987:Dibenzothiazepines / Q000009:adverse effects / Q000627:therapeutic use*; D006970:Disorders of Excessive Somnolence / Q000139:chemically induced; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D006966:Hyperprolactinemia / Q000139:chemically induced; D008297:Male; D011569:Psychiatric Status Rating Scales; D000069348:Quetiapine Fumarate; D018967:Risperidone / Q000009:adverse effects / Q000627:therapeutic use*; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D003987:Dibenzothiazepines; D000069348:Quetiapine Fumarate; D018967:Risperidone