Objective: This review reports the incidence of hyperprolactinemia, its relationship with genotype, and prolactin-related side effects in children and adolescents treated with antipsychotics.
Method: Data on prolactin levels were available for haloperidol, pimozide, risperidone, olanzapine, clozapine, ziprasidone, and quetiapine. Twenty-nine studies were selected after a literature search in the English Medline/Embase/Psychinfo/EBM databases (1965 to August, 2008).
Results: All antipsychotics, except clozapine, ziprasidone, and quetiapine, increase the mean prolactin level from baseline values of 8.0 ng/mL to 25-28 ng/mL after 4 weeks of treatment (reference range 0-15 ng/mL). The most and best data are available for risperidone. Five risperidone studies (n = 577) show an increase of prolactin level from 7.8 ng/mL to 17.7 ng/mL after 1 year of treatment, and two risperidone studies (n = 60) show an increase from 7.4 ng/mL to 24.9 ng/mL after 2 years of treatment. Aggregated over all antipsychotics, prolactin-related side effects, such as gynecomastia, galactorrhea, irregular menses, and sexual dysfunction, were reported by 4.8% of the children and adolescents. No data are available on bone mineral density in relation to antipsychotic-induced hyperprolactinemia in children and adolescents. Prolactin levels may be influenced by the genetic differences that influence prolactin metabolism and D2 dopamine receptor density.
Conclusion: Persistent elevation of prolactin for periods up to 2 years has been documented in maintenance treatment with risperidone. Very limited long-term data of pimozide, olanzapine, and quetiapine prohibit drawing conclusions for these antipsychotics. Systematic long-term observational studies, including specific questionnaires as well as physical examination, are needed to investigate prolactin-related side effects of antipsychotic treatment in children and adolescents.