Metabolic derangements with olanzapine and risperidone in schizophrenia spectrum and other psychotic disorders: A 24-week prospective study

Schizophrenia spectrum and other psychotic disorders are common disorders often requiring long-term treatment with atypical antipsychotics, which might cause metabolic dysfunctions. We aimed to study the metabolic dysfunctions with olanzapine and risperidone in patients with schizophrenia spectrum and other psychotic disorders. We also explored the incidence of new-onset metabolic syndrome and its predictors.

This was a 24-week prospective observational study conducted at a teaching hospital in North India. The patients were prescribed olanzapine or risperidone. Anthropometric measurements (waist circumference, weight, body mass index, blood pressure) and biochemical investigations (triglycerides, high-density lipoproteins, fasting plasma glucose) were recorded at baseline and after 24 weeks. Metabolic syndrome was defined using the International Diabetes Federation definition. Statistical tests used were Fisher's exact test, paired t-test, unpaired t-test, and logistic regression.

A total of 45 patients, 30 on olanzapine and 15 on risperidone completed the study. Statistically significant changes occurred in all variables with olanzapine while with risperidone statistically significant changes occurred in all variables except waist circumference and fasting plasma glucose. Statistically greater changes in mean values between the two were noted only for high-density lipoprotein with olanzapine. 20% of patients developed metabolic syndrome with non-significant between drug differences. Baseline triglyceride predicted the development of the metabolic syndrome.

Olanzapine and risperidone cause metabolic derangements and statistically significant differences may not exist between them. Baseline triglyceride levels might predict subsequent metabolic syndrome.