Metformin usage in the treatment of risperidone induced hyperprolactinemia in an adolescent patient with bipolar disorder type 1: a case report

Antipsychotic drugs are used in the treatment of many mental disorders, especially psychotic disorders, bipolar disorders and neurodevelopmental disorders in children and adolescents. Antipsychotics, along with their effectiveness in treatment, have also been associated with a number of adverse effects. One of these is hyperprolactinaemia (hyperPRL) that occurs with antipsychotics. This situation is thought to be due to dopamine blockade in the tuberoinfundibular pathway, which has an effect on prolactin release. Hereby, we present a 15 year old female adolescent bipolar disorder type 1 case who developed hyperprolactinaemia with risperidone treatment which was ameliorated with metformin use (850–2000 mg/day). Although there are studies showing that metformin can be used in the treatment of hyperprolactinaemia, as far as we know, there are not enough studies on the use of metformin in adolescents. Future studies are needed to elucidate the risk factors, aetiological mechanism and treatment alternatives of this adverse effect, which occurs due to antipsychotics and may negatively affect medication compliance.