Is cabergoline (dopamine receptor agonist) safe to use during pregnancy?

Cabergoline Safety in Pregnancy

Cabergoline should not be used during pregnancy unless the potential benefit clearly outweighs the possible risks, as it is not recommended for use in pregnant women according to FDA labeling. 1

Safety Profile and Recommendations

Cabergoline, a dopamine agonist commonly used to treat hyperprolactinemia, carries specific warnings regarding pregnancy:

• The FDA drug label explicitly states that dopamine agonists should not be used in patients with pregnancy-induced hypertension (preeclampsia, eclampsia, postpartum hypertension) unless the potential benefit outweighs the possible risk 1

• According to the FDA label, cabergoline should be used during pregnancy only if clearly needed, as adequate and well-controlled studies in pregnant women are lacking 1

• Women should discontinue cabergoline when pregnancy is confirmed or suspected, and notify their physician immediately 1

Evidence from Observational Studies

Despite the FDA warnings, several observational studies have provided data on cabergoline exposure during pregnancy:

• A 12-year observational study of 380 pregnancies with early cabergoline exposure showed no apparent increase in the risk of miscarriage or fetal malformations compared to the general population 2

• Another study of 100 pregnancies initiated under cabergoline treatment reported a 10% spontaneous miscarriage rate and a 3.4% malformation rate, which was comparable to their control group 3

• Most studies involve women who discontinued cabergoline upon pregnancy confirmation, with only limited cases of continued use throughout pregnancy 4, 5

Management Algorithm for Women Taking Cabergoline

1. Pre-pregnancy planning:

   • Discuss pregnancy intentions with patients on cabergoline
   • Consider switching to bromocriptine before planned conception as it has more extensive safety data in pregnancy 4

2. Upon pregnancy confirmation:

   • Immediately discontinue cabergoline in most cases 1, 4
   • Perform pregnancy test if menstrual irregularity or pregnancy is suspected

3. Special circumstances for continued use:

   • Consider continuing cabergoline only in cases of macroadenomas with risk of significant tumor growth during pregnancy 5
   • This decision should be made after careful risk-benefit assessment and thorough patient counseling

4. Monitoring during pregnancy if previously on cabergoline:

   • Regular clinical assessment for symptoms of tumor growth (headaches, visual disturbances)
   • MRI evaluation (without gadolinium) if clinically indicated for women with macroadenomas
   • Monitor for potential complications, though observational data suggests these are rare 2, 3

Important Considerations and Caveats

• Bromocriptine remains the preferred dopamine agonist for women planning pregnancy as it has been proven safe in over 6,000 pregnancies 4

• Cabergoline should not be given to women postpartum who are breastfeeding or planning to breastfeed, as it will interfere with lactation 1

• The risk of tumor growth during pregnancy should be weighed against the potential risks of cabergoline exposure to the fetus

• While observational data is reassuring, the FDA labeling reflects the lack of controlled studies and the need for caution

• Cabergoline has a long half-life, meaning early fetal exposure may occur even when discontinued immediately upon pregnancy confirmation

In conclusion, while observational studies suggest relative safety of early cabergoline exposure in pregnancy, the drug should generally be discontinued upon pregnancy confirmation unless there are compelling reasons to continue treatment, such as significant risk of complications from tumor growth.