Hiperprolactinémia em doentes psiquiátricos.

Resumo

Hyperprolactinemia is a common, but neglected, adverse effect of conventional antipschycotics and of some of the atypical antipshycotics. It occurs in almost 42% of men and in 75% of women with schizophrenia who are treated with prolactin-raising antipshycotics, even though it has aroused minimal interest within the scientific community when compared with extra-pyramidal effects. Conventional antipsychotics and some of the atypical antipsychotics, such as risperidone, paliperidone, amisulpride and zotepine, are frequently associated with the raise in prolactin plasma levels. Because of this increment in prolactin secretion, they are usually known as prolactin-raising antipshycotics. On the contrary, some of the atypical antipsychotics, such as clozapine, quetiapine, olanzapine, aripiprazole and ziprazidone, have a minimal or no significant effect in prolactin levels, being known as prolactin-sparing antipsychotics. Hyperprolactinemia clinical symptoms include gynaecomastia, galactorrhoea, menstrual irregularities, infertility, sexual dysfunction, acne and hirsutism. Some of these symptoms are due to the prolactin direct action in body tissues, while a couple of them can be due to a hypothalamic-pituitary-gonadal axis dysregulation mediated by the elevation of prolactin. Some studies seem to point the evidence of an association between hyperprolactinemia and long-term consequences, such as bone mineral density decrement and breast cancer. However, these results must be confirmed through further studies. Antipsychotic treatment is the most common cause of hyperprolactinemia in psychiatric patients. However, the evidence of a prolactin increased plasma level demands the differential diagnosis with other pathologies, such as hyphotalamic and pituitary neoplasic disease. The management of a patient with antipsychotic-induced hyperprolactinemia must be adapted to each patient and it may include a reduction in the dosage of the offending antipsychotic, switching to a prolactin-sparing antipsychotic or the use of a dopamine receptor agonist, such as bromocriptine, cabergoline and amantadine. Given the osteopenic and osteoporosis risk, combined oral contraceptives must be considered in female patients in fertile age which have amenorrhoea for at least a one year period. With the exception of the Maudsley Prescribing Guidelines and the National Collaborating Centre for Mental Health, none of the current international psychiatric guidelines recommend a routine baseline prolactin determination, neither periodic prolactin levels without the presence of any hyperprolactinemia symptoms.