Metformin for Weight Loss Due to Psychotic Meds

Dramatic weight gain caused by anti-psychotic medicines, such as Clozaril (clozapine), Zyprexa (olanzapine) and Risperdal (risperidone), put people with schizophrenia and other psychotic disorders in the unenviable position of having to choose mental health over physical health. However, a 2008 study published in the February issue of "The American Journal of Psychiatry," found the diabetes drug metformin to be of significant value in controlling the weight of patients on anti-psychotic medication.

Metformin and Lifestyle

• According to the study's lead researcher, Dr. Ren-Rong Wu, metformin combined with lifestyle improvements, such as healthier eating and exercise, produced the most significant weight control. However, metformin without a change in the patients' lifestyle, controlled weight more significantly than lifestyle change alone.

Study Design

• The subjects, age 18 to 50, were recruited from a university mental hospital. Because weight gain disproportionately affects previously untreated patients, all 128 subjects in the study were recently diagnosed with schizophrenia, and had begun low-dose, antipsychotic treatment with atypical, anti-psychotic drugs, Clorazil, Zyprexa, Risperdal or sulpiride, a drug used in Asia and Europe. All had gained at least 10 percent of their body weight since beginning their medication regimen. Randomly selected members of the group were assigned treatment with either metformin alone, metformin with lifestyle intervention, placebo and lifestyle intervention, or placebo alone.

Results (after 12 weeks)

• The group assigned to the placebo alone gained an average of 6.8 pounds. Those assigned to the placebo with lifestyle changes lost 3.1 pounds, and a fraction of an inch around their waistlines. The metformin alone group lost an average of 7.1 pounds, and their waistlines shrank a half-inch. The metformin plus lifestyle-intervention group lost 10.4 pounds, on average, and almost an inch around their waists.

Metformin

• According to the study, metformin is a "hepatic-selective insulin sensitizer," and has been used in the treatment of diabetes for years. An earlier study (Klein, et al) had discovered the drug to be "safe and effective in abrogating weight gain and decreases [sic] insulin sensitivity and abnormal glucose metabolism," so Dr. Wu and team hypothesized that metformin might be useful in preventing obesity and glucose metabolic dysfunction in people taking atypical, antipsychotic medicine. With weight gain being one of the main reasons people with psychosis live 30 years less than the general population, metformin may prove to be a real lifesaver, not only by controlling weight but checking diabetes, as well.