Endocrine Abstracts

Background
A fear of rising serum prolactin concentrations (PRO) and pituitary tumour enlargement undoubtedly result in over-treatment of some patients with pathological hyperprolactinaemia. In recent years, our unit has adopted pragmatic criteria for discontinuing dopamine agonist (DA) therapy in selected patients. These include: small (or no) abnormality of pituitary imaging; presentation PRO<2,000milliunits per litre; small DA dose; stable PRO; women with a history of pregnancy or menopause.
Objectives
To evaluate the outcomes of a DA discontinuation policy.
Methods and subjects
A retrospective study was performed on 62 consecutive subjects with hyperprolactinaemia attending an endocrine clinic. Notes were reviewed and data collected on relevant administrative, demographic and clinical details.
Results
87% (54) of patients received DA, 13 of whom discontinued medication (5 idiopathic hyperprolactinaemia, 5 microprolactinomas, 2 polycystic ovary syndrome and 1 drug-induced). The average duration off treatment was 26 months. Patients selected for a trial off DA had a lower mean latest PRO than those not selected (816milliunits per litre v 1012milliunits per litre). Having discontinued DA, clinical evidence for deterioration was assessed on symptoms and signs, PRO, visual fields and cranial imaging where appropriate. There were no cases of clinically significant pituitary enlargement off medication. Of 11 menopausal women, 18% (2) received a trial off medication and 82% (9) did not. Mean latest PRO were similar in both groups (1,656milliunits per litre v 1,705milliunits per litre). 6 of 13 women with a history of pregnancy stopped DA. Their mean latest PRO was lower than that of the women of childbearing age without a history of pregnancy (787milliunits per litre v 1,004milliunits per litre).
Conclusions
With selective DA discontinuation, 21% (13/62) of our study population safely discontinued treatment for a mean of 26 months. There was also no evidence of clinically significant enlargement of pituitary lesions or sustained rise in PRO.