Categorical prevalence and severity of hyperprolactinaemia in two UK cohorts of patients with severe mental illness during treatment with antipsychotics.

Hyperprolactinaemia may be associated with hidden longer-term consequences, such as osteoporosis, bone fractures, pituitary tumours and breast cancer. Prolactin data from clinical trials is not always reported in a categorical manner and does not always allow the risk of hyperprolactinaemia to be evaluated for specific patient cohorts. Patients participating in a physical health management programme in the UK for severe mental illness patients--the Well-being Support Programme--had prolactin measurements made regardless of symptoms. Prolactin data from the complete cohort of 178 patients receiving antipsychotics in Leeds and London are reported. Hyperprolactinaemia was measured in 33.1% but more commonly in females than males (47.3% and 17.6%) and was associated with all antipsychotics except clozapine. The highest prevalence rates were found in amisulpride (n=20) 89%, risperidone long-acting intramuscular injection (LAIM) 67% (n=6) and risperidone (n=30) 55% used as antipsychotic monotherapy. Clinically Significant hyperprolactinaemia (>1000 mIU/L approximately 47 ng/ml) was measured in 15.8% of patients, predominantly in females. Levels >2000 mIU/L approximately 95 ng/ml in 6.2% of the complete cohort. Clinicians may wish to add prolactin measurement to the routine laboratory parameters currently measured for some antipsychotics and should be advised of the potential longer-term consequences of hidden hyperprolactinaemia.