From the Guidelines
Cabergoline works primarily as a dopamine receptor agonist, specifically targeting D2 receptors in the pituitary gland to inhibit prolactin secretion. This mechanism of action is supported by recent guidelines, such as the consensus guideline for the diagnosis and management of pituitary adenomas in childhood and adolescence, which recommends cabergoline as first-line therapy for prolactinoma 1. The medication's long half-life and high affinity for dopamine receptors make it an effective treatment for hyperprolactinemia and prolactin-secreting pituitary adenomas.
Key aspects of cabergoline's mechanism of action include:
- Binding to D2 receptors in the pituitary gland to mimic the action of dopamine and inhibit prolactin secretion from lactotroph cells
- Decreasing prolactin levels in the bloodstream, which is effective for treating hyperprolactinemia and prolactinomas
- Having a long half-life of approximately 65-110 hours, allowing for less frequent dosing compared to other dopamine agonists
- Acting on dopamine receptors in other brain regions, which can explain some of its side effects and off-label uses
The efficacy and safety of cabergoline have been demonstrated in various studies, including a randomized controlled trial that showed cabergoline was superior to bromocriptine in normalizing prolactin levels and resuming ovulatory cycles or achieving pregnancy, with fewer adverse events reported 1. Overall, cabergoline's mechanism of action as a dopamine receptor agonist makes it a highly effective treatment for prolactinoma and hyperprolactinemia, with a favorable efficacy and safety profile compared to other dopamine agonists.
From the FDA Drug Label
The secretion of prolactin by the anterior pituitary is mainly under hypothalamic inhibitory control, likely exerted through release of dopamine by tuberoinfundibular neurons. Cabergoline is a long-acting dopamine receptor agonist with a high affinity for D2 receptors Results of in vitro studies demonstrate that cabergoline exerts a direct inhibitory effect on the secretion of prolactin by rat pituitary lactotrophs.
The mechanism of action of cabergoline is as a long-acting dopamine receptor agonist with a high affinity for D2 receptors, exerting a direct inhibitory effect on the secretion of prolactin by pituitary lactotrophs 2.
- Key points:
- Dopamine receptor agonist
- High affinity for D2 receptors
- Inhibitory effect on prolactin secretion
From the Research
Mechanism of Action of Cabergoline
- Cabergoline is a synthetic ergoline that shows high specificity and affinity for the dopamine D2 receptor 3.
- It is a potent and very long-acting inhibitor of prolactin secretion, with prolactin-lowering effects occurring rapidly and lasting for several days 3, 4.
- The mechanism of action of cabergoline involves binding to dopamine D2 receptors, which inhibits the secretion of prolactin from the pituitary gland 3, 4.
Comparison with Bromocriptine
- Cabergoline has been compared to bromocriptine in several studies, with results showing that cabergoline is more effective in normalizing prolactin levels and reducing tumor size 5, 6, 7.
- Cabergoline also has a better tolerability profile than bromocriptine, with fewer adverse effects reported 5, 6, 7.
- The studies suggest that cabergoline is a more effective and better-tolerated option than bromocriptine for the treatment of hyperprolactinemia 5, 6, 7.
Efficacy and Safety
- Cabergoline has been shown to be effective in normalizing prolactin levels, restoring gonadal function, and reducing tumor size in patients with hyperprolactinemia 3, 5, 6, 7.
- The safety profile of cabergoline is generally good, with common adverse effects including nausea, vomiting, headache, and dizziness 3, 5, 6, 7.
- However, cabergoline has been associated with a lower risk of serious adverse effects, such as thromboembolic events, compared to bromocriptine 3.