Treatment of Hyperprolactinemia With the Non-ergoline Dopamine Agonist Ropinirole

Treatment of prolactin secreting pituitary tumors with traditional ergot dopamine agonist drugs can be limited by medication side effects, pharmacologic resistance, and by concerns regarding the potential risk of cardiac valve disease. The overall goal of this project is therefore to evaluate, for the first time, the efficacy and tolerability of the selective D2/D3 receptor non-ergot dopamine agonist ropinirole for the treatment of prolactinomas. This proposal will establish the pharmacologic profile of this medication when used to treat hyperprolactinemia in patients with prolactinomas and will determine the impact of long-term ropinirole administration on critical clinical parameters including serum prolactin levels, gonadal function, and tumor regression, in order to establish ropinirole's utility as a new, clinically efficacious, safer and more tolerable therapeutic option for the treatment of prolactinomas that may prove particularly useful in patients with underlying cardiac valve disease and in those with resistance or intolerance to ergot dopamine agonists.

Inclusion criteria

• Ages 18-70 years
• Prolactin level (PRL) ≥2 times upper limit of normal
• Pituitary adenomas on MRI ≤ 1.5cm in greatest diameter and ≥ 5mm from the optic chiasm
• Normal renal and liver function
• Agrees to barrier contraception if pre-menopausal

Exclusion criteria

• Use of medications known to interfere with PRL secretion and PRL and Ropinirole (ROP) metabolism
• Use of another dopamine agonist during the 4 weeks prior
• Pituitary stalk compression on MRI
• History of visual field abnormalities or previous radiation
• Untreated hypothyroidism
• Consumption of > 2 alcoholic drinks per day
• Pregnancy