A 1-year double-blind study of 2 doses of long-acting risperidone in stable patients with schizophrenia or schizoaffective disorder

• Published in: The journal of clinical psychiatry Vol. 67; no. 8; pp. 1194 - 1203
• Main Authors: SIMPSON, George M, MAHMOUD, Ramy A, LASSER, Robert A, KUJAWA, Mary, BOSSIE, Cynthia A, TURKOZ, Ibrahim, RODRIGUEZ, Steven, GHARABAWI, Georges M
• Format: Journal Article
• Language: English
• Published: Memphis, TN Physicians Postgraduate Press 01-08-2006
• Subjects: Adult; Adult and adolescent clinical studies; Antipsychotic Agents - administration & dosage; Antipsychotic Agents - therapeutic use; Biological and medical sciences; Delayed-Action Preparations; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Female; Hospitals, Psychiatric; Humans; International Cooperation; Longitudinal Studies; Male; Medical sciences; Neuropharmacology; Patient Readmission; Pharmacology. Drug treatments; Prospective Studies; Psycholeptics: tranquillizer, neuroleptic; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Psychopharmacology; Psychoses; Psychotic Disorders - drug therapy; Psychotic Disorders - psychology; Risperidone - administration & dosage; Risperidone - therapeutic use; Schizophrenia; Schizophrenia - drug therapy; Schizophrenic Psychology; Secondary Prevention; Time Factors; Treatment Outcome; Human; Schizoaffective psychosis; Atypical antipsychotic; Psychotropic; Neuroleptic; Dopamine antagonist; Serotonin antagonist; Schizophrenia; Serotonine receptor; Chemotherapy; D2 Dopamine receptor; Treatment; Double blind study; Risperidone
• ISSN: 0160-6689; 1555-2101
• DOI: 10.4088/JCP.v67n0804

This study examined the effects of 2 doses of long-acting risperidone injection in patients with schizophrenia or schizoaffective disorder.
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.
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.
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.