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Positive prolactin response to bromocriptine in 2 patients with cabergoline-resistant prolactinomas. Endocr Pract 2011;17(3):e55-8



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Scopus ID

2-s2.0-79955085743 (requires institutional sign-in at Scopus site)   16 Citations


OBJECTIVE: To describe a positive prolactin response to bromocriptine treatment in 2 patients with cabergoline-resistant prolactinomas.

METHODS: We report the patients' clinical presentations, laboratory test results, imaging findings, and clinical courses.

RESULTS: Patient 1 had a 5-mm pituitary microadenoma that was initially diagnosed at age 30 years. After initial diagnosis, she was treated with transvaginal bromocriptine for 9 years and then subsequently went untreated for 2 years. After developing symptoms of amenorrhea, decreased libido, and hyperprolactinemia, oral cabergoline, 0.5 mg twice weekly, was initiated. Her prolactin concentration remained elevated at 80 ng/mL while taking cabergoline. Her prolactin concentration decreased to 13 ng/mL after her regimen was switched to bromocriptine, 5 mg daily. Patient 2 had a 17-mm pituitary macroadenoma that was initially diagnosed at age 15 years. Oral cabergoline was started at 0.5 mg twice weekly and increased to 1 mg 3 times weekly when prolactin levels continued to rise to 340 ng/mL over 18 months. After visual field defects developed, transsphenoidal surgery was performed. One year after surgery, magnetic resonance imaging showed a 6- to 7-mm pituitary adenoma, and there was a gradual rise in serum prolactin. Her serum prolactin concentration continued to rise to 212 ng/mL with increasing tumor size over 3 years. Cabergoline was discontinued and oral bromocriptine was initiated at a dosage of 10 mg daily. After 4.5 months of bromocriptine therapy, her serum prolactin concentration decreased to 133 ng/mL. However, after 2 months, the macroadenoma continued to increase in size and a visual field defect developed, so another transsphenoidal operation was performed.

CONCLUSIONS: Although cabergoline is generally preferred to bromocriptine for the treatment of patients with prolactinomas because of its better tolerance profile and greater effectiveness, in patients with cabergoline-resistant prolactinomas, a bromocriptine trial should be considered a safe, relatively inexpensive, and well-tolerated alternative.

Author List

Iyer P, Molitch ME


Pallavi Iyer MD Chief, Associate Professor in the Pediatrics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Antineoplastic Agents
Drug Resistance, Neoplasm
Hormone Antagonists
Pituitary Neoplasms
Treatment Outcome