Prolactin levels during long-term risperidone treatment in children and adolescents

This analysis was designed to investigate prolactin levels in children and adolescents on long-term risperidone treatment and explore any relationship with side effects hypothetically attributable to prolactin (SHAP).

Data from 5 clinical trials (total N = 700) were pooled for this post hoc analysis. Children and adolescents aged 5 to 15 years with subaverage intelligence quotients and conduct or other disruptive behavior disorders received risperidone treatment (0.02-0.06 mg/kg/day) for up to 55 weeks. Outcome measures analyzed included serum prolactin levels, reported adverse events, and the conduct problem subscore of the Nisonger Child Behavior Rating Form.

Mean prolactin levels rose from 7.8 ng/mL at baseline to a peak of 29.4 ng/mL at weeks 4 to 7 of active treatment, then progressively decreased to 16.1 ng/mL at weeks 40 to 48 (N = 358) and 13.0 ng/mL at weeks 52 to 55 (N = 42). There was no relationship between pro-lactin levels and age. Females returned to a mean value within the normal range (

With long-term risperidone treatment in children and adolescents, serum prolactin levels tended to rise and peak within the first 1 to 2 months and then steadily decline to values within or very close to the normal range by 3 to 5 months.