A 1-year double-blind study of 2 doses of long-acting risperidone in stable patients with schizophrenia or schizoaffective disorder.
OBJECTIVE
This study examined the effects of 2 doses of long-acting risperidone injection in patients with schizophrenia or schizoaffective disorder.


METHODS
This 52-week, prospective, randomized, double-blind, multicenter, international study included clinically stable outpatients with schizophrenia or schizoaffective disorder (DSM-IV criteria). Settings included physicians' offices and clinics. Patients received a fixed dose of long-acting risperidone (25 or 50 mg) every 2 weeks. Primary outcome was time to relapse, defined as either re-hospitalization or other exacerbation criteria. Other assessments included the Positive and Negative Syndrome Scale, Clinical Global Impressions-Severity of Illness scale, and functional and quality-of-life measures. Safety was assessed via treatment-emergent adverse events, laboratory tests, and movement disorder rating scales. Data were collected from December 2002 to September 2004.


RESULTS
A total of 324 patients were randomized to 25 mg (N = 163) or 50 mg (N = 161) of long-acting risperidone. Time to relapse was comparable (p = .131) for both groups. Projected median time to relapse was 161.8 weeks (95% CI = 103.0 to 254.2) with 25 mg and 259.0 weeks (95% CI = 153.6 to 436.8) with 50 mg. One-year incidences of relapse were 21.6% (N = 35) and 14.9% (N = 24), respectively (p = .059). Psychiatric hospitalization was the reason for relapse for 16 (10%) in the 25-mg group and 10 (6%) in the 50-mg group. Patients experienced statistically significant but modest improvements at endpoint in most measures (i.e., psychotic symptoms, functioning, movement disorder severity) with both doses, with no significant between-group differences.


CONCLUSIONS
In this 1-year study, long-acting risperidone was associated with low relapse and rehospitalization rates, indicating that doses of 25 to 50 mg are appropriate for long-term treatment in schizophrenia.
Simpson
George M
GM
Department of Psychiatry, Keck School of Medicine of the University of Southern California, Los Angeles, USA.
Mahmoud
Ramy A
RA
Lasser
Robert A
RA
Kujawa
Mary
M
Bossie
Cynthia A
CA
Turkoz
Ibrahim
I
Rodriguez
Steven
S
Gharabawi
Georges M
GM
D000328:Adult; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D003692:Delayed-Action Preparations; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006778:Hospitals, Psychiatric; D006801:Humans; D007391:International Cooperation; D008137:Longitudinal Studies; D008297:Male; D010359:Patient Readmission; D011446:Prospective Studies; D011618:Psychotic Disorders / Q000188:drug therapy* / Q000523:psychology; D018967:Risperidone / Q000008:administration & dosage / Q000627:therapeutic use*; D012559:Schizophrenia / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D055502:Secondary Prevention; D013997:Time Factors; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D003692:Delayed-Action Preparations; D018967:Risperidone