Comparative Effects of Risperidone, Olanzapine and Aripiprazole on Serum Prolactin Levels in Patients with Psychiatric Disorders

Introduction

Risperidone, olanzapine and aripiprazole are widely used in the management of psychiatric disorders but may influence serum prolactin levels. This study aimed to compare the effects of these drugs on serum prolactin levels among patients with psychiatric disorders.

Methods

A comparative cross-sectional study was conducted at the Institute of Medicine, Maharajgunj Medical Campus, Kathmandu, Nepal. A total of 90 patients aged 18–49 years were enrolled and equally divided into three groups receiving risperidone, olanzapine and aripiprazole (n=30 each). The duration of treatment was comparable among groups (approximately > 6 weeks). Venous blood (5 mL) was collected in the morning under standard conditions and serum prolactin levels were measured using CLIA. Ethical approval was obtained. Data were analyzed using SPSS. Normality was assessed using the Shapiro–Wilk test which showed non-normal distribution of data (p<0.05). Risperidone p = 0.007, Olanzapine p = 0.009 and Aripiprazole p = 0.029. Therefore, the Kruskal–Wallis test was used to compare serum prolactin levels among groups. A p-value <0.05 was considered statistically significant.

Results

The median (interquartile range) serum prolactin levels were highest in the risperidone group [52.16 (68.47) ng/mL] followed by the olanzapine group [23.05 (32.15) ng/mL] and the aripiprazole group [6.25 (8.55) ng/mL] showing a statistically significant difference among groups (p<0.001). Pairwise comparisons demonstrated significant differences between risperidone and aripiprazole and between risperidone and olanzapine.

Conclusion

Serum prolactin levels differed significantly among the three drug groups with risperidone showing the highest elevation and aripiprazole the least effect. These findings indicate a differential impact of Risperidone, Olanzapine and Aripiprazole on serum prolactin levels.