Animal studies have revealed evidence of fetotoxicity at doses producing maternal toxicity; in rabbits administered this drug IV, maternal toxicity (decreased body weight gain) occurred at 20 mg/kg/day (equal to 4 times the proposed therapeutic maintenance dose of 100 mg/day based on relative body surface area) and was associated with fetal toxicity (reduced fetal weights and incomplete ossification). In rats, this drug crossed the placental barrier and was detected in fetal plasma. There are no controlled data in human pregnancy.

AU TGA pregnancy category B3: Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. Studies in animals have shown evidence of an increased occurrence of fetal damage, the significance of which is considered uncertain in humans.

US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.

This drug should not be used during pregnancy unless the benefit outweighs the risk to the fetus.

AU TGA pregnancy category: B3
US FDA pregnancy category: Not assigned.

Risk summary: Based on results from animal studies, this drug may cause fetal harm when used during pregnancy; no data available on use of this drug in pregnant women to inform a drug-related risk.

Comments:
-Pregnant women should be apprised of the potential harm to the fetus.
-According to some authorities: Women of childbearing potential should use effective contraception; patients should be advised to contact physician immediately if they become pregnant while taking this drug.

See references

Use is not recommended unless the benefit outweighs the risk.
-According to some authorities: A decision should be made to discontinue breastfeeding or discontinue the drug, taking into account the importance of the drug to the mother.

Excreted into human milk: Unknown
Excreted into animal milk: Yes

Comments:
-Developmental and health benefits of breastfeeding should be considered as well as the mother's clinical need for this drug.
-The effects in the nursing infant are unknown; potential side effects in the breastfed child due to this drug or the mother's underlying condition should be considered.

See references