Comparison of effects on plasma prolactin levels between aripiprazole and risperidone

Objective: To compare the effects on plasma prolactin (PRL) level and its correlation with clinical characteristics between aripiprazole and risperidone in female schizophrenia at firs-onset stage. Method: One-hundred and twenty female patients with first-onset schizophrenia were randomly divided into aripiprazole group (n = 60) and risperidone group (n = 60) for eight therapeutic weeks. The positive and negative syndrome scale (PANSS) was evaluated before and after therapy 8 weeks. The plasma PRL level was measured by radioimmunoassay before and after 8-week therapy. Results: There was no significant difference between the reduced rate of total scores of PANSS after 8 weeks in aripiprazole group and that in risperidone group (49.79±23.48 v.s. 63.30±22.66, p0.05). The plasma PRL level increased after 8-week risperidone therapy, but reduced after aripiprazole therapy (26.92±9.48 v.s. -25.25±8.07, P0.001). There were significant correlations between the dispersion of plasma PRL levels and the PRL levels before and after after 8-week therapy (r=0.41,r=0.79,p0.01, respectively). No significant correlations were found between the dispersion of plasma PRL level and the reduction of total PANSS score, weight gain, dosage of drugs or other characteristics (P0.05). Conclusion: Aripipazole is as effective as risperidone in the therapy of patients with first-onset schizophrenia. However, Aripipazole with less influence on plasma PRL level, which differentiate from risperidone and has no relationship with clinical characteristics.