Endocrine Abstracts

Dopamine agonists (DA) are the first line treatment for patients with symptomatic prolactinoma and aims to lower prolactin, reduce adenoma size and restore gonadal function. This treatment is effective in the majority of patients and DA resistance s reported in around 10% of patients on cabergoline and 20–30% of those on bromocriptine. Established consensus on the optimal duration of DA therapy is lacking. Given the potential adverse effects of DAs in the long-term and the possibility of remission of hyperprolactinaemia after treatment cessation, a trial of DA withdrawal is included in the management algorithm of prolactinomas. The timing of this has not been clearly established. Current guidelines suggest that treatment may be tapered and subsequently withdrawn in patients who have normal prolactin and no evidence of tumour on imaging and have received DA treatment for at least two years. Nevertheless, the probability of maintenance of remission is low with a meta-analysis showing persisting normoprolactinaemia after DA withdrawal in 21% of micro- and 16% of macroprolactinomas. The recurrences are most likely to occur within a year after stopping DA therapy. Discontinuation of DA therapy can also be considered in females who have reached menopause. The risk of recurrence of hyperprolactinaemia is lower in this group compared with premenopausal women who had a trial of DA withdrawal. Nonetheless, adenoma regrowth has been demonstrated in patients of this group necessitating regular monitoring of the cases with persistent or progressively increasing prolactin values.