The Effects of Novel Antipsychotics on Glucose and Lipid Levels

Background: The novel antipsychotics are extensively used based on their favorable extrapyramidal side effect profiles. However, accumulating evidence suggests that these agents, particularly clozapine and olanzapine, have serious side effects of their own, including weight gain and elevated glucose and triglyceride levels. The goal of this study is to compare the effects of novel antipsychotics clozapine, olanzapine, risperidone, and quetiapine and typical antipsychotics haloperidol and fluphenazine on glucose and lipid levels.

Method: The charts of 590 patients were retrospectively reviewed. Of those, 215 patients had adequate laboratory data for inclusion. Glucose and lipid level data from 2¹/₂ years before and after initiation of the target antipsychotic were included. Covariates, including patients’ age, the duration of antipsychotic treatment, other medications that may affect glucose or lipid levels, and the initial laboratory values, were controlled for in the analyses.

Results: Glucose levels were increased from baseline for patients treated with clozapine, olanzapine, and haloperidol. There were statistically and clinically significant differences among the medications’ effects on lipid profiles (p < .05). Those receiving clozapine and olanzapine demonstrated statistically significant increases in triglyceride levels compared with the other groups. Over one third of patients treated with any of the novel antipsychotics had clinically meaningful triglyceride elevations.

Conclusion: It has been shown that novel antipsychotics are associated with weight gain. This risk factor along with others, such as elevated glucose and triglyceride levels, compounds the risk for coronary artery disease. Routine monitoring of glucose and lipid levels during treatment with novel antipsychotics should be advocated.