Prolactin Levels During Long-term Risperidone Treat- ment in Children and Adolescents: a Cross-sectional Study

Objective: Risperidone is a commonly prescribed antipsychotic in children and adolescents with a wide spectrum of mental illnesses. Of all atypical antipsychotics, it has the greatest propensity to induce hyperprolactinaemia. This study assessed the correlation between treatment with risperidone and serum prolactin levels in an out-patient paediatric population. Methods: A cross-sectional retrospective medical chart review of 25 children (18 males and 7 females, age range 7–15 years, mean age 11.2 ±2.0 years) treated solely with risperidone (mean dose 1.6 ±0.9 mg per day) was undertaken. Serum prolactin levels were obtained after at least 3 months (mean 30.4 ±12.7 months) of treatment. Results: Eighty percent of subjects were found to have serum prolactin above the upper limit of normal, with no statistically significant gender difference in the extent of prolactin elevation. Risperidone-induced hyperprolactinaemia was found to be dose-dependent (males, r = 0.55, p =0.017; females, r = 0.92, p = 0.003). No correlation is present between the duration of treatment and serum prolactin levels Conclusions: Risperidone-induced hyperprolactinaemia in children is a real adverse effect with potentially serious clinical implications. However, neither this study nor previously published studies have formally evaluated these adverse effects as yet. Further studies are thus required in this special age group to address this issue (German J Psychiatry 2008; 11: 45-50).