Low dose vs standard dose of antipsychotics for relapse prevention in schizophrenia: meta-analysis.
BACKGROUND
It remains unknown as to whether the antipsychotic dose needed for the acute-phase treatment of schizophrenia is also necessary for relapse prevention.


OBJECTIVE
To compare the efficacy between standard dose [(World Health Organization daily defined dose (DDD)] vs low dose (≥50% to <1 DDD) or very low dose (<50% DDD) for relapse prevention in schizophrenia.


METHODS
Double-blind, randomized, controlled trials with a follow-up duration of ≥24 weeks, including ≥2 dosage groups of the same antipsychotic drug for relapse prevention in schizophrenia, were searched using MEDLINE, the Cochrane Central Register of Controlled Trials, and EMBASE (last search: August 2009).


METHODS
Data on overall treatment failure, hospitalization, relapse, and dropouts due to side effects were extracted and combined in a meta-analysis.


RESULTS
Thirteen studies with 1395 subjects were included in this meta-analysis. Compared with the standard-dose treatment, the low-dose therapy did not show any statistically significant difference in overall treatment failure or hospitalization, while the standard dose showed a trend-level (P = .05) superiority in risk of relapse. The very low-dose group was inferior to the standard-dose group in all efficacy parameters. No significant difference was found in the rate of dropouts due to side effects between either standard dose vs low dose or very low dose.


CONCLUSIONS
Although antipsychotic treatment with ≥50% to <1 DDD may be as effective as standard-dose therapy, there are insufficient clinical trial data to draw firm conclusions on standard- vs low-dose maintenance antipsychotic therapy for schizophrenia.
Uchida
Hiroyuki
H
Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan. mcn41320@biglobe.ne.jp
Suzuki
Takefumi
T
Takeuchi
Hiroyoshi
H
Arenovich
Tamara
T
Mamo
David C
DC
D000208:Acute Disease; D000328:Adult; D014150:Antipsychotic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008134:Long-Term Care; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology / Q000523:psychology; D016032:Randomized Controlled Trials as Topic; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D012565:Schizophrenic Psychology; D055502:Secondary Prevention; D017211:Treatment Failure
D014150:Antipsychotic Agents