A long-acting repeatable form of bromocriptine as long-term treatment of prolactin-secreting macroadenomas: a multicenter study.

OBJECTIVE: To assess the efficacy and tolerability of monthly injections of the long-acting repeatable bromocriptine in patients with macroprolactinomas. DESIGN: Open and prospective trial. SETTING: This multicenter trial was carried out in seven university hospitals. PATIENTS: Forty-two patients with prolactin (PRL)-secreting macroadenomas. INTERVENTIONS: Fifty to 200 mg of the drug were administered intragluteally every 28 days for 6 to 24 months. MAIN OUTCOME MEASURES: The efficacy was assessed by repetitive plasma PRL measurements, visual field determinations, and computed tomography scan examinations. RESULTS: After the first 50-mg injection, the mean percentage decrease of PRL levels was 71% from baseline on day 14; between days 1 and 28, PRL levels were suppressed to normal in nine cases, and a clear tumor shrinkage was documented in 21% of the patients. Normalization of PRL secretion was obtained in 62%, and a clear-cut reduction in tumor size in 50% of the patients after 6 months of treatment. CONCLUSIONS: The long-acting repeatable form of bromocriptine was a well tolerated and quickly effective treatment in most of these patients with macroprolactinomas.