Cabergoline: an ergot derivative, is a potent dopamine receptor agonist on D₂ receptors. Rat studies show cabergoline has a direct inhibitory effect on pituitary lactotroph (prolactin) cells.^[1] It is frequently used as a first-line agent in the management of prolactinomas due to higher affinity for D₂ receptor sites, less severe side effects, and more convenient dosing schedule than the older bromocriptine.

Although cabergoline is commonly described principally as a dopamine D₂ receptor agonist, it also possesses significant affinity for the D₃, D₄, 5-HT_1A, 5-HT_2A, 5-HT_2B, 5-HT_2C, α_2B- receptors, and moderate/low affinity for the D₁ and 5-HT₇ receptors. Cabergoline functions as an agonist at all of these receptors except for 5-HT₇ and α_2B-, where it acts as an antagonist.