Endocrine Abstracts

Elevated serum prolactin (PRL) is common, with many potential causes. We performed a retrospective audit of patients with hyperprolactinaemia from 2006 to 2008, aiming to identify the clinical indications for prolactin testing, the aetiology identified and the treatment instigated. Medical notes for 83 patients (55 female, mean age 41 years (range 17–95)) with PRL >700 mU/l were retrospectively reviewed. Indications for testing included: seizure or suspected seizure (35), headache (14), routine psychiatric admission (13), oligomenorrhoea (11), galactorrhoea (7) and erectile dysfunction (3). Aetiology of elevated PRL was: presumed seizure-related (30), medication-related (16), pituitary tumour (15), macroprolactinaemia (8), pregnancy (2), and unknown (12). Medications associated with hyperprolactinaemia included: neuroleptics (12), selective serotonin re-uptake inhibitors (SSRIs) (3), and dopamine antagonists (1). Mean PRL for the different medications was 1596, 1361 and 1052 mU/l respectively (P=0.49, ANOVA). Four patients on neuroleptics/SSRIs had medication adjustments based on the PRL result. Of 15 patients with pituitary tumours, 4 were macroprolactinomas, 4 microprolactinomas and 7 other pituitary tumours, with mean PRL of 9066, 2576 and 1343 mU/l respectively (P=0.07, ANOVA). Mean PRL in 30 patients with seizure-related hyperprolactinaemia was 1328 mU/l. Repeat blood testing to confirm normalization of prolactin was performed in one patient. In patients with macroprolactinaemia, mean PRL was 1008 mU/l, with mean post-fractionation PRL 302 mU/l. In conclusion, seizure was the most common cause of an elevated PRL, but follow-up of these patients to rule out co-incidental pituitary disease was poor. A large number of tests were performed, many of which did not alter management.