Benefit should outweigh risk

AU TGA pregnancy category: B3
US FDA pregnancy category: Not Assigned

Risk Summary: In animal studies, developmental toxicity occurred at clinically relevant doses; there are no adequate data on the developmental risk associated with use in pregnant women

Comments:
-Women of reproductive potential should be counseled on effective contraception; women using levonorgestrel-containing contraceptives will need to use an additional non-hormonal form of contraception while using this drug and for 1 month after discontinuation.
-To monitor the pregnancy outcomes in women exposed to antiepileptic drugs (AEDs), a pregnancy registry has been established; pregnant women are encouraged to enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry by visiting http://www.aedpregnancyregistry.org.

This drug and/or its metabolites cross the placenta in rats. Oral administration to rats from early gestation to weaning at doses of 1, 3 or 10 mg/kg/day (0.8, 2 and 8 times the maximum recommended human dose [MRHD]) was associated with fetal and pup deaths at the mid and high doses (associated with maternal toxicity) and delayed sexual maturation in males and females at the highest dose tested. In rabbits, oral administration throughout organogenesis revealed embryo lethality and maternal toxicity at the mid and high doses tested (3 and 10 mg/kg/day). There are limited amounts of data in human pregnancy (less than 300 pregnancies). 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.

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In lactating rats, this drug and/or its metabolites (measured at 10 days postpartum) had levels peak at 1 hour and measure 4 times higher than plasma levels. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for the drug and any potential adverse effects on the breastfed child from the drug or from the underlying maternal condition.

Benefit should outweigh risk

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

Comments:
-The effects on the nursing infant and on milk production are unknown.
-If this drug is required by the mother, monitor the infant for drowsiness, agitation, and adequate weight gain; monitor for developmental milestones, especially in younger, exclusively breastfed infants and when using combinations of drugs.

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