High levels of sugar in the blood, also known as hyperglycemia, is a common finding in individuals taking atypical antipsychotics who are thought to have normal blood sugar levels.

Over a 2-year period, Dr. Michael J. Sernyak, of the VA Connecticut Healthcare System, New Haven, Connecticut, and colleagues examined the frequency of undiagnosed high blood sugar in 647 patients taking atypical antipsychotics, including Clozaril (clozapine), Risperdal (risperidone), Zyprexa (olanzapine), Seroquel (quetiapine), or Geodon (ziprasadone). Of these subjects, 153 had a fasting blood sugar result.

The investigators found that blood sugar levels were normal in 70 percent subjects, elevated in 25 percent and very elevated in a little more than 5 percent. No significant differences in race, ethnicity, age, body mass index or psychiatric diagnosis were observed between those with normal and patients with abnormal blood sugar results.

When the authors analyzed the antipsychotic medications prescribed, they found that significantly more patients receiving Clozaril were in the elevated blood sugar group than in the normal blood sugar group. No significant differences were observed for any of the other medications.

The authors say the finding that nearly one in three patients receiving atypical antipsychotics who are thought to have normal blood sugar levels actually have “demonstrable and clinically significant abnormalities” of glucose metabolism argues for periodic screening in even large outpatient populations.”

SOURCE: Journal of Clinical Psychiatry December 2005.