The relationship between prolactin response and clinical efficacy of risperidone in acute psychotic inpatients

Hyperprolactinemia can be induced by dopamine D2 receptor-binding drugs such as antipsychotic drugs. The author investigated the relationship between changes in prolactin (PRL) and clinical efficacy of risperidone. In this study, 27 acute psychotic inpatients completed a 12-week trial of risperidone. At baseline and at 2, 4, 8, and 12 weeks after beginning medication, the author measured PRL, assessed hyperprolactinemia-related symptoms, and administered the Brief Psychotic Rating Scale (BPRS). Risperidone treatment significantly elevated serum PRL level (range: 26.9 ng/ml-320.0 ng/ml). The increases of PRL in females were higher than males. The changes in serum PRL levels were not significantly correlated with the improvements in total BPRS scores. PRL-related symptoms such as irregular menstruation, galactorrhea, or erectile dysfunction occurred in nine subjects (7 females and 2 males) whose serum PRL levels increase very highly after 2 weeks of risperidone. In conclusion, our study suggests that the changes in serum PRL levels were not significantly correlated with clinical efficacy of risperidone.