Effectiveness of metformin in reducing weight gain caused by antipsychotics

• Register: SLCTR
• Last refreshed on: 27 April 2013
• Main ID: SLCTR/2010/004
• Date of registration: 02/07/2010
• Primary sponsor: Faculty of Medicine
• Public title: Effectiveness of metformin in reducing weight gain caused by antipsychotics
• Scientific title: Metformin for treatment of atypical antipsychotic induced weight gain: a randomized double blind placebo controlled trial
• Date of first enrolment: 15/7/2010
• Target sample size: 128 (64+64)
• Recruitment status: Recruiting
• URL: http://www.slctr.lk/trial_details.asp?reg_id={E03C8EAC-0F26-4584-B3F3-1499E3F73D14}
• Study type: Interventional
• Study design: Randomized double blind placebo controlled trial; Subjects; Subjects fulfilling inclusion and exclusion criteria will be recruted from the psychiatry unit at National Hospital of Sri Lanka and Asiri Hospital Colombo; Randomization; Patients will be assigned to intervention and control groups based on random numbers generated by the computer. Principal investigator will be blind to the assignment. Patients will be blind to the treatment of metformin or placebo. But they will know the antipsychotic drug they are receiving. Research assistants measuring the outcome measures will be blind to assignment; Medication will be supplied in coded containers

Countries of recruitment

Sri Lanka

Contacts

• Name: Dr. Varuni de Silva
• Affiliation: Senior Lecturer in Psychiatry

• Name: Dr. Varuni de Silva
• Affiliation: Senior Lecturer Psychiatry

Key inclusion & exclusion criteria

Inclusion criteria: 1. Patients diagnosed with schizophrenia or schizoaffective disorder according to ICD-10 research criteria

2.Age > 18 years

3.Treated with olanzapine, risperidone or clozapine

4. Gained more than 10% of the pre treatment body weight

Exclusion criteria: 1. Those concurrently treated with other psychotropics known to cause weight gain, (lithium carbonate, carbamazepine, sodium valproate and antidepressants)

2. Patients too ill to consent

3. Patients previously diagnosed with diabetes

4. Pregnant patients

5. Patients with impaired renal functions before enrollment
(Sample size calculation is based on an expected difference in weight of Body Weight Gain of between the 2 groups, a power of 80%, and a Type I error of 5%. Sample size required in each group=64)


Age minimum:
Age maximum:
Gender:

Health Condition(s) or Problem(s) studied

Schizophrenia

Intervention(s)

The study drug is metformin. Intervention group will be given metformin and the control group a similar appearing placebo one tablet tds.


Intervention group Metformin dose- commencing dose 250mg b.d. after reviewing for tolerance will be increased if necessary to a maximum of 500mg tds.


During the first week after commencement of metformin FBS will be done daily to identify any hypoglycaemia.


Both groups will be given advice regarding nutrition and exercise but will not be assigned specific diet or exercise program.

Primary Outcome(s)

change in total body weight

Secondary Outcome(s)

Body Mass Index (BMI), waist/hip ratio, fasting blood sugar, lipid profile

Secondary ID(s)

Nil known

Source(s) of Monetary Support

Faculty of Medicine,Colombo