Relationship between prolactin secretion, and plasma risperidone and 9-hydroxyrisperidone concentrations in adolescents with schizophreniform disorder

SummaryBackgroundTreatment with the atypical antipsychotic risperidone can result in elevated prolactin levels. To date, the relationships between plasma concentrations of prolactin, risperidone and its active 9-hydroxy-metabolite have been little investigated in adolescents with psychosis.MethodsProlactin levels were determined at baseline in 16 hospitalized drug-naïve adolescents meeting DSM-IV criteria for schizophreniform disorder. Prolactin, risperidone, 9-hydroxyrisperidone levels were subsequently determined after 3 weeks of oral risperidone treatment.ResultsCompared with pretreatment values, prolactin levels at endpoint were significantly increased (p<0.00001) and correlated with risperidone doses (r=0.58, N=16, p<0.02), and plasma levels of risperidone (r=0.60, N=16, p<0.02) and 9-hydroxyrisperidone (r=0.54, N=16, p=0.03).ConclusionsThese data suggest that risperidone's effect on prolactin release is dose-dependent in adolescents and is linked to both plasma risperidone and 9-hydroxyrisperidone concentrations.