Adjunctive Aripiprazole Treatment for Risperidone-Induced Hyperprolactinemia: An 8-Week Randomized, Open-Label, Comparative Clinical Trial

OBJECTIVE The present study aimed to evaluate the efficacy and safety of adjunctive aripiprazole treatment in schizophrenia patients with risperidone-induced hyperprolactinemia. METHODS One hundred and thirteen patients who were receiving a stable dose of risperidone were randomly assigned to either adjunctive aripiprazole treatment (10 mg/day) (aripiprazole group) or no additional treatment (control group) at a 1:1 ratio for 8 weeks. Schizophrenia symptoms were measured using the Positive and Negative Syndrome Scale (PANSS). Rating scales and safety assessments (RSESE, BARS, UKU) were performed at baseline and at weeks 4 and 8. Serum levels of prolactin were determined at baseline and at weeks 2, 4, 6 and 8. Metabolic parameters were determined at baseline and again at weeks 4 and 8. RESULTS One hundred and thirteen patients were enrolled in this study, and 107 patients completed the study (54 in the aripiprazole group, and 53 in the control group). PANSS-total scores in the aripiprazole group decreased significantly at week 4 (P = 0.003) and week 8 (P = 0.007) compared with the control group. PANSS-negative scores in the aripiprazole group also decreased significantly at week 4 (P = 0.005) and week 8 (P< 0.001) compared with the control group. Serum levels of prolactin in the aripiprazole group decreased significantly at week 2 (P< 0.001), week 4 (P< 0.001), week 6 (P< 0.001) and week 8 (P< 0.001) compared with the control group. There were no significant differences in changes of Fasting Plasma Glucose, Total cholesterol, Triglycerides and High Density Lipoprotein within each group at week 4 and 8 execpt low density lipoproteins. There was no significant difference in the incidence of adverse reactions between the two groups. CONCLUSIONS Adjunctive aripiprazole treatment may be beneficial in reducing serum levels of prolactin and improving negative symptoms in schizophrenia patients with risperidone-induced hyperprolactinemia. TRIAL REGISTRATION chictr.org ChiCTR-IOR-15006278.