From the Guidelines
Cabergoline is the first-line treatment for a woman with cyclical mastalgia and galactorrhea with hyperprolactinemia, as it has been shown to be effective in reducing serum prolactin concentrations and inducing tumour shrinkage, with a superior effectiveness and lower adverse effect profile compared to other dopamine agonists 1.
Key Points
- Dopamine agonists reduce pituitary-origin hyperprolactinaemia of any cause, and cabergoline is the dopamine agonist of choice due to its longer half-life and greater affinity for the dopamine receptor 1.
- Cabergoline has been shown to be effective in normalizing prolactin levels, resuming ovulatory cycles, and achieving pregnancy, with a lower rate of adverse events compared to bromocriptine 1.
- Small nocturnal dose increments of cabergoline can help diminish adverse effects such as gastrointestinal intolerance and postural hypotension 1.
- Resistance to dopamine agonists is usually defined as failure to achieve normoprolactinaemia or less than 50% reduction in tumour area after 3-6 months of maximally tolerated doses, and may require consideration of alternative treatments such as surgery or radiotherapy 1.
Treatment Approach
- Start with a low dose of cabergoline and gradually increase as needed and tolerated, to minimize adverse effects.
- Monitor prolactin levels and adjust the dose accordingly, with the goal of achieving normoprolactinaemia.
- Consider alternative treatments such as surgery or radiotherapy if dopamine agonist resistance or intolerance occurs, or if vision deteriorates or does not improve on medical therapy.
From the Research
Treatment Options for Cyclical Mastalgia and Galactorrhea with Hyperprolactinemia
- For women with cyclical mastalgia, Vitex agnus-castus (VAC) has been shown to be effective in relieving breast pain intensity and lowering increased serum prolactin levels 2.
- VAC is considered a safe treatment option with only mild and reversible adverse events, and its effectiveness is comparable to pharmaceutical therapies such as dopamine agonists and hormonal contraceptives 2.
- Dynamic tests of prolactin release, such as those using TRH or domperidone, may be useful in predicting the response to endocrine therapy in patients with cyclical mastalgia 3.
- In cases of galactorrhea, treatment is not always necessary, but if prolactin levels are elevated, cabergoline is the preferred medication for treatment of hyperprolactinemia 4.
- Bromocriptine, a prolactin inhibitor, has also been shown to be effective in treating severe cyclical mastalgia, with significant improvements in breast pain, tenderness, and nodularity, as well as reduced serum prolactin levels 5.
Diagnostic Considerations
- Basal serum prolactin levels may be elevated in women with cyclical mastalgia, and a significant positive correlation between oestradiol and prolactin has been found in these patients 6.
- A pregnancy test should be obtained for premenopausal women presenting with galactorrhea, and renal function, as well as thyroid-stimulating hormone levels, should also be assessed 4.
- Magnetic resonance imaging of the pituitary gland may be necessary if the cause of hyperprolactinemia is unclear after a medication review and laboratory evaluation 4.