Pregnant rats receiving this drug orally during the period of organogenesis at doses approximately 7, 13, 22 and 27 times the MRHD showed maternal toxicity at the 2 higher doses (decreased body weight, food consumption and convulsions); no adverse effects were observed on embryofetal development. In pregnant rabbits, administration 2, 4 and 8 times the MRHD, maternal toxicity was observed at 4 times or greater the MRHD (significant body weight loss and decreased food consumption); death of 1 animal and convulsions in 2 occurred at 8 times the MRHD. When administered to pregnant rats from gestation day 7 through lactation day 20, maternal toxicity including death, CNS events including convulsions, and significant decreases in weight and food consumption occurred at 22 times the MRHD; fetal toxicity including stillbirths, postnatal pup mortality (due to lack of milk and/or failure to nurse), and decreased pup length and weight were also observed. A single female rat failed to produce milk at 13 times the MRHD resulting in pup mortality. Available case reports from clinical trials and postmarketing reports have not yielded any information to determine a drug-associated risk. There are no controlled data in human pregnancy

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.

Benefit should outweigh risk

US FDA pregnancy category: Not Assigned

Risk Summary: There is insufficient data to inform a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes in humans; animal data has shown maternal and embryofetal toxicity in rats at doses 13 times the maximum recommended human dose (MRHD) and in rabbits at greater than 4 times MRHD when administered during organogenesis.

Comments:
-A pregnancy registry has been established to monitor outcomes in women exposed to this drug during pregnancy; information about the registry is available at 1-800-833-7460
-Effective contraception should be discussed with women of childbearing potential; contraception should be continued for at least 21 days after treatment.
-Hormonal contraceptive may be less effective in women receiving this drug and therefore an alternative method of effective contraception should be discussed.

See references

This drug is present in the milk of lactating rats. The level in milk tended to be 1 to 3 times higher in milk compared to plasma.

Benefit should outweigh risk

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

Comments:
-There are no data on the effects of this drug on the breastfed infant or its effects on milk production; some authorities consider this drug contraindicated while breastfeeding.

See references