Which Dopamine agonist is most commonly used to treat prolactin-secreting pituitary adenomas?

• A. Amantadine (Symmetrel)
• B. Bromocriptine (Parlodel)
• C. Methylphenidate (Ritalin)
• D. Dextroamphetamine (Dexedrine)

Answer: (B)

Prolactin secretion is inhibited by dopamine acting on D2 receptors in the pituitary. A dopamine agonist that targets these receptors can directly suppress prolactin release and often shrink a prolactin-secreting pituitary adenoma. Bromocriptine fits this role precisely: it’s a dopamine D2 receptor agonist (ergot-derived) that effectively lowers prolactin levels and reduces tumor size, making it a standard treatment for prolactinomas.

The other drugs listed are not used for this purpose. Amantadine increases dopamine activity but does not specifically suppress prolactin via pituitary D2 receptors, and methylphenidate and dextroamphetamine are stimulants used for ADHD/other conditions, not for treating prolactinomas.