Pituitary Microadenomas Medication

Updated: Nov 16, 2020
  • Author: Bernard Corenblum, MD, FRCPC; Chief Editor: George T Griffing, MD  more...
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Medication Summary

If the tumor is secreting excess hormone (eg, prolactin, growth hormone, corticotropin, gonadotropins (rarely), thyroid-stimulating hormone [TSH] [rarely), initiate appropriate medical therapy as described in the articles on Acromegaly and Cushing disease. For the most common microadenoma, ie, prolactinomas, administer a dopaminergic drug such as bromocriptine or cabergoline (see Hyperprolactinemia).


Dopamine agonists

Class Summary

Dopamine agonists directly stimulate dopamine receptors on the lactotrope. The dopaminergic neurons in the tuberoinfundibular process normally inhibit the secretion of prolactin from the anterior pituitary by secreting dopamine. In a study of 827 patients with hyperprolactinemia (81 of whom had macroadenomas), Corenblum found that treatment with bromocriptine normalized hyperprolactinemia in 85%, reversed symptoms in 93%, and reversed hypogonadism in 94%. [21] Similar results are reported with cabergoline, which has less intolerance and resistance. [22]

Bromocriptine (Parlodel)

Bromocriptine is a semisynthetic ergot alkaloid derivative, strong dopamine D2-receptor agonist, and partial dopamine D1-receptor agonist. It inhibits prolactin secretion, with no effect on other pituitary hormones. It may be administered with food to minimize the possibility of gastrointestinal irritation. Bromocriptine is given 1-2 times per day.

Cabergoline (Dostinex)

Cabergoline is a long-acting dopamine receptor agonist with a high affinity for D2 receptors. Prolactin secretion by the anterior pituitary is primarily under hypothalamic inhibitory control exerted through dopamine. Cabergoline is administered 1-2 times per week.