Metformin for treatment of antipsychotic-induced weight gain in a South Asian population with schizophrenia or schizoaffective disorder: A double blind, randomized, placebo controlled study.
BACKGROUND
Antipsychotic-induced weight gain causes serious health problems. We investigated the efficacy and safety of metformin in treating antipsychotic-induced weight gain in South Asian patients.


METHODS
Sixty six adult patients with schizophrenia or schizoaffective disorder treated, with atypical antipsychotics, and who had increased by more than 10% their pre treatment body weight, were randomly assigned to receive metformin or placebo in a double-blind study. Patients received usual treatment and metformin 500 mg or placebo twice daily for 24 weeks. The primary outcome measure was change in body weight from baseline to week 24. Linear mixed models were used in the analysis.


RESULTS
Mean change in body weight in the metformin group was -1.56 kg (95% CI=-3.06 to -0.05) and 1.0 kg (95% CI=0.03-1.97) in the placebo group. Between-group difference was 2.56 kg. At 24 weeks the between-group difference showed significant time-by-treatment interaction (F=3.23, p=0.004). Between-group difference in BMI showed significant time-by-treatment interaction (F=3.41 p=0.03). There was no significant difference in waist-hip ratio or fasting blood sugar.


CONCLUSIONS
Metformin is effective in reducing weight in South Asian patients with schizophrenia or schizoaffective disorder who had increased their body by more than 10% after treatment with atypical antipsychotics.
Department of Psychological Medicine, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka varunidesilva2@yahoo.co.uk.
Varuni A
VA
de Silva
Department of Psychological Medicine, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka.
Madhubhashinee
M
Dayabandara
Senior Registrar in Psychiatry, University Psychiatry Unit, National Hospital of Sri Lanka, Colombo, Sri Lanka.
Hiranya
H
Wijesundara
Senior Registrar in Psychiatry, University Psychiatry Unit, National Hospital of Sri Lanka, Colombo, Sri Lanka.
Thushani
T
Henegama
Senior Registrar in Psychiatry, University Psychiatry Unit, National Hospital of Sri Lanka, Colombo, Sri Lanka.
Heshan
H
Gunewardena
Senior Registrar in Psychiatry, University Psychiatry Unit, National Hospital of Sri Lanka, Colombo, Sri Lanka.
Chathurie
C
Suraweera
Department of Psychological Medicine, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka.
Raveen
R
Hanwella
D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects*; D001786:Blood Glucose / Q000187:drug effects; D015992:Body Mass Index; D001835:Body Weight / Q000187:drug effects; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D009765:Obesity / Q000188:drug therapy; D011618:Psychotic Disorders / Q000188:drug therapy*; D012559:Schizophrenia / Q000188:drug therapy*; D015430:Weight Gain / Q000187:drug effects*
D014150:Antipsychotic Agents; D001786:Blood Glucose; D007004:Hypoglycemic Agents; D008687:Metformin
Schizophrenia; Sri Lanka; antipsychotics; metformin; weight gain