Antipsychotic-induced hyperprolactinemia: a cross-sectional survey.

OBJECTIVE: To investigate the prevalence of hyperprolactinemia and common hyperprolactinemia-related symptoms and explore the association between them in patients using a modern antipsychotic drug regimen and, in addition, investigate the prevalence of the inert fraction of prolactin called macroprolactin, which, to our knowledge, has not been investigated systematically in this population before. Macroprolactin may cause misdiagnosis of hyperprolactinemia.
METHOD: A cross-sectional design was applied, and 106 patients who were using antipsychotics for symptoms of psychosis were included.
RESULTS: Hyperprolactinemia was found in 39% of the patients. Women were overrepresented in the group with the highest prolactin levels. Macroprolactin was not detected in any cases. Several of the second-generation antipsychotics were associated with hyperprolactinemia. Pearson correlation between prolactin level and symptoms revealed no association, and some patients did not report any symptoms despite grossly elevated levels of biologically active prolactin.
CONCLUSIONS: The results suggest that hyperprolactinemia is still an important and prevalent side effect. In patients using antipsychotics with prolactin-elevating potential, prolactin levels should be routinely measured to prevent potential long-term complications of "silent" hyperprolactinemia, although we are still in the early stages of knowing what to do with the information.