How It Works
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 medicine helps to
normalize interactions between the pituitary gland and the
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 medicines.1
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
Bromocriptine can cause mild to moderate side effects,
Side effects from bromocriptine can be minimized by building up
slowly to a full dose or by administering tablets vaginally rather than
Cabergoline causes minimal side effects compared to bromocriptine,
but its effects on the fetus are not as fully researched.
See Drug Reference for a full list of side effects. (Drug Reference
is not available in all systems.)
What To Think About
While you are taking bromocriptine, avoid alcohol and use care when
driving or operating machinery.
Some women are resistant to bromocriptine or cannot tolerate it.
About 70% to 85% of these women have good results with cabergoline as a
treatment for increased prolactin levels.1
If ovulation does not begin after 2 months of bromocriptine or
recombinant human FSH, or human menopausal gonadotropin (hMG) treatment may be added.
Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.
Speroff L, Fritz MA (2005). Induction of ovulation. In
Clinical Gynecologic Endocrinology and Infertility, 7th
ed., pp. 1175-1213. Philadelphia: Lippincott Williams and Wilkins.