The second-generation antipsychotics are effective for treating psychotic disorders and incur fewer motor side effects than are commonly experienced with the use of first-generation antipsychotics. However, their use is commonly associated with weight gain and metabolic disturbances. This study examined weight and metabolic changes with two widely used antipsychotics, risperidone and olanzapine; addressing the issue of early monitoring for metabolic side effects.
This 8-week double blind randomized trial included patients with schizophrenia or schizoaffective disorder (N = 377) randomly assigned to risperidone (2-6 mg/day) or olanzapine (5-20 mg/day). Weight, BMI, HbA1C, total cholesterol (TC), LDL-C, HDL-C and triglycerides (TG) were monitored.
Mean BMI increases were higher in the olanzapine group as compared to risperidone (1.3 kg/m(2)(SD = 0.13) vs. 0.7 kg/m(2) (SD = 0.13)(p < 0.001). Increases in mean TC (13.5 mg/dl (SD 2.4), LDL-C (11.0 mg/dl (SD 2.2)) and TG (14.8 mg/dl (SD = 7.6)) occurred in the olanzapine group while significant changes in TC (-3.9 mg/dl (SD = 2.5)) and TG (-32.8 mg/dl (SD = 7.8)) were noted in the risperidone group. Men (not women) on olanzapine had higher than expected increases in lipids given the amount of weight gain. Baseline values and prior therapy did not contribute to the significant differences, however BMI increases (p = 0.0002) were linked to study discontinuation in both drug groups.
The fact that significant metabolic changes occurred (both positive and negative) in eight weeks is important to clinical care. Monitoring for metabolic changes may be important within the first eight weeks of treatment, as changes can be determined very early in antipsychotic treatment.