Bromocriptine and cabergoline reduce the body's amount of prolactin, a hormone produced by the pituitary gland. Excess prolactin makes a woman stop ovulating; in a man, it reduces sperm production, impairs sex drive, and causes impotence (erectile dysfunction).
Why It Is Used:
Bromocriptine or cabergoline may be used when a woman is not ovulating because she has high levels of prolactin in her blood.
Bromocriptine may be used to treat a man whose reproductive functions are impaired because he has abnormally high levels of prolactin.
High prolactin is commonly produced by a pituitary tumor. If you have elevated prolactin levels, you will need further testing to find whether a tumor is present. Bromocriptine is used to treat male infertility only if it is associated with a prolactin-producing pituitary tumor; the medication helps to normalize interactions between the pituitary gland and the testicles.
How Well It Works:
Among women who have ovulation problems due to excess prolactin, 70% to 90% will begin having menstrual periods on a regular cycle and 50% to 75% will begin ovulating normally while taking these medications.
Ovulation rates do not reflect the fact that well-timed intercourse is necessary to conceive, and some pregnancies miscarry. In any group of women, ovulation rates are higher than pregnancy rates, which are higher than live birth rates.
Cabergoline causes few side effects, the most common being headache.
Bromocriptine can cause mild to moderate side effects, including:
* Nasal stuffiness.
* Dizziness, lightheaded.
Side effects from bromocriptine can be minimized by building up slowly to a full dose or by administering tablets vaginally rather than orally.
Cabergoline causes minimal side effects compared to bromocriptine, but its effects on the fetus are not as fully researched.