MON-282 Treatment of Hyperprolactinemia with Ropinirole: An Open-Label Dose Escalation Study

Purpose Treatment of hyperprolactinemia and prolactinomas with ergoline dopamine agonists (DAs) can be complicated by intolerance and resistance. Ropinirole (ROP) is a low cost selective D2/D3 receptor non-ergot DA, approved for treatment of Parkinson’s disease and Restless Leg Syndrome, that has been shown to acutely lower prolactin levels (PRL). This study investigated the efficacy and tolerability of long-term ROP therapy in patients with hyperprolactinemia. Methods & Results Ten healthy women (21-45 yrs) with hyperprolactinemia were treated with ROP (0.25-6.0mg/d) for 6 months in an open-label dose escalation study. Clinical and biochemical status was assessed monthly and ROP doses were up-titrated to achieve normal PRL levels, restore menses, and eliminate galactorrhea. Two subjects had macroprolactinomas, 7 had microprolactinomas, and 1 had idiopathic hyperprolactinemia. 8/10 had previously been treated with cabergoline and/or bromocriptine. 5/10 were intolerant and 1/10 was resistant to ergot DAs. Pituitary MRIs were performed at baseline and 6 months.ROP was initiated at 0.25mg QHS in 9/10 subjects. One subject with severe DA intolerance was initiated on 0.125mg QHS. Subjects reaching a total daily dose (TDD) > 2.0mg/d were transitioned to ROP extended release. At study completion, TDDs ranged from 1-6mg/d, with a median TDD of 2mg/d. Baseline PRL levels were 136 ± 49ng/ml (1.9-25ng/ml). Stable PRL normalization was achieved in 50% of subjects. Of the subjects achieving normal PRL, 4 had microadenomas and 1 had idiopathic hyperprolactinemia, and the median effective TDD was 1mg/d (1-4mg/d, range). Among those not achieving PRL normalization, PRL decreased 46 ± 5.4% (Mean ± SEM) from baseline, at a median TDD of 4.0mg/d (2-6mg/d, range). In the subject with documented resistance to ergot DAs, PRL decreased from 529 to 320ng/ml, after 3 months of ROP on the maximum dose studied (6mg/d), but rose to 690ng/ml at 6 months. During ROP treatment, menses normalized in 57%, and galactorrhea resolved in 67% of affected subjects. At study completion, tumor size was unchanged in 7/8 prolactinomas. A 20% decrease in tumor size was observed in one macroadenoma, accompanied by a 30% reduction in PRL levels. There were no changes in BP, HR, weight, renal or kidney function. Mild adverse effects (AEs) were recorded in 80% of subjects. Fatigue (60%), nausea (40%), and headache (20%) were most common. Reported AEs declined after month 1 and ROP was not discontinued due to intolerance. Conclusion These data provide support for the efficacy of ROP in the treatment of hyperprolactinemia in patients with microprolactinomas and idiopathic hyperprolactinemia. While further study is needed, ROP treatment for hyperprolactinemia could be considered in patients with ergot DA intolerance or significant cardiac valve disease.