1. Home>
2. Specialties>
3. Psychiatry>
4. Summary and Comment

Glucose Regulation Impaired by Atypical Antipsychotic Drugs

These researchers found that abnormal glycemic regulation was associated most strongly with clozapine and olanzapine and was independent of adiposity.

Recent reports of an association between type II diabetes mellitus and atypical antipsychotic drugs (Journal Watch Psychiatry May 8 2002) and observations of weight gain in patients using particular antipsychotics have heightened concerns about the adverse effects of these medications, which generally are better tolerated and safer than older neuroleptics are. In this study, 17 schizophrenic patients taking typical neuroleptics, 31 schizophrenic patients taking atypicals (risperidone, olanzapine, or clozapine), and 31 controls consumed oral glucose drinks at least 9 hours after fasting. Plasma levels of glucose, insulin, C-peptide, glucagons, and cortisol were determined before and up to 75 minutes after the glucose load.

Mean plasma glucose levels at fasting and after the glucose load were significantly elevated in olanzapine and clozapine users, compared with controls and neuroleptic users. Risperidone users had elevated mean glucose levels compared with controls but not with neuroleptic users. At 75 minutes, mean plasma insulin levels were still increasing in clozapine users but were falling in the other patients, suggesting an element of insulin resistance associated with clozapine. All changes were independent of body mass index.

Comment: Abnormal glycemic regulation, which in this study was associated most strongly with clozapine and olanzapine and which was independent of adiposity, raises concerns that some atypical antipsychotics may pose potential risks, such as diabetes and cardiovascular diseases. Further work is necessary to determine whether actual medical complications develop more frequently in patients taking these atypical antipsychotics and whether regular monitoring of fasting blood sugar levels (or some other parameter) can reduce morbidity.

— Steven Dubovsky, MD

Published in Journal Watch Psychiatry May 23, 2002

Citation(s):

Newcomer JW et al. Abnormalities in glucose regulation during antipsychotic treatment of schizophrenia. Arch Gen Psychiatry 2002 Apr; 59:337-45.

• Original article (Subscription may be required)
• Medline abstract (Free)