MGH Docs Link Diabetes to Anti-Psychotic Meds

Massachusetts General Hospital researchers have linked two of the most commonly prescribed drugs for schizophrenia to increased risk of diabetes.

Study subjects taking the anti-psychotic medications clozapine and olanzapine developed significant insulin resistance, a major factor in diabetes, according to a study published in “The Archives of General Psychiatry” this month.

Dr. David Henderson, an MGH psychiatrist, said he started looking into the problem several years ago after noticing patients were “developing diabetes at rates quite higher than we would expect.”

“We’ve seen reports of patients developing insulin resistance who have been on the drug just a few weeks up to 10 years,” he said.

Clozapine and olanzapine are sold under the brand names Clozaril and Zyprexa, respectively.

“Clinicians need to recognize there is a risk and inform patients about it as well as do a risk assessment and monitor for these potential side effects,” Henderson said, adding, “If there are other risk factors for diabetes, these aren’t the first drugs you go to.”

However, he said, both drugs remain important tools for treating schizophrenia cases resistant to other medications.

A spokesman for Cloziril maker Novartis Pharmaceuticals said the company has long included a caution in its prescribing instructions warning doctors to monitor any patients with diabetes or known risk factors for the disease.