Lilly and Novartis schizophrenia drugs may increase diabetes risk

Study results have been published in the Archives of General Psychiatry, one of the JAMA/Archives journals. According to background information in the article, life expectancy in patients with schizophrenia is up to 20% shorter than that of the general population.

Furthermore, according to the article, newer atypical anti-psychotic agents such as Clozaril and Zyprexa have recently been linked to “several forms of morbidity, including obesity; hyperlipidemia; type 2 diabetes mellitus; and diabetic ketoacidosis (a severe complication of diabetes).”

Dr David Henderson from Massachusetts General Hospital and Harvard Medical School, Boston, and colleagues, evaluated 36 non-obese outpatients with schizophrenia or schizoaffective disorder who were treated with clozapine, olanzapine, or another medication, risperidone (marketed as Janssen’s Risperdal).

Participants were given a diet to follow to maintain body weight and were told to fast for 12 hours prior to undergoing a frequently sampled intravenous glucose tolerance test.

“Both nonobese clozapine- and olanzapine-treated groups displayed significant insulin resistance and impairment of glucose effectiveness compared with risperidone-treated subjects,” the researchers found.

The authors concluded: “Psychiatrists and primary care professionals should be aware that patients treated with clozapine and olanzapine may be at increased risk for insulin resistance, even if not obese. Insulin resistance is associated with hyperlipidemia, hypertension, and cardiovascular disease and over time may increase the risk for diabetes mellitus in vulnerable individuals.”

Both Novartis and Eli Lilly’s shares have seen a slight downturn following the publication of these results.