Animal studies have revealed evidence of malformations (teratogenicity) and anomalies at exposures lower than human exposures. After pregnant rabbits received oral doses during organogenesis, severe maternal toxicity was observed at 450 mg/kg (about 0.75 times the human exposure at the 450 mg clinical dose); at 150 mg/kg (about 0.5 times the human exposure by AUC at the clinical dose), 2 animals aborted, 1 died prematurely, and mean fetal body weight decreased. A dose-dependent increase of skeletal malformations occurred at doses at least 5 mg/kg (about 0.003 times the human exposure by AUC at the clinical dose), and a case of spina bifida was seen at 5 mg/kg. There are no controlled data in human pregnancy.

AU TGA pregnancy category D: Drugs which have caused, are suspected to have caused or may be expected to cause, an increased incidence of human fetal malformations or irreversible damage. These drugs may also have adverse pharmacological effects. Accompanying texts should be consulted for further details.

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.

Use is not recommended unless clearly needed.
-According to some authorities: This drug must not be used during pregnancy.

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

Risk summary: Based on animal studies and its mechanism of action, this drug can cause fetal harm.

Comments:
-Pregnant women, women of childbearing potential, and male patients with female partners of childbearing potential should be apprised of the potential harm to the fetus.
-Pregnancy testing is recommended in women of childbearing potential before starting this drug; according to some authorities, pregnancy status should be verified is such patients before starting therapy.
-Females of childbearing potential and male patients with female partners of childbearing potential should be advised to use effective contraception during therapy and for at least 1 week after the last dose.

See references

Breastfeeding is not recommended during use of this drug and for 1 week after the last dose.

Excreted into human milk: Unknown
Excreted into animal milk: Data not available

Comments:
-No information is available on the clinical use of this drug during breastfeeding.
-Because this drug is highly bound to plasma proteins, the amount in milk is likely to be low; however, it is potentially toxic in the breastfed infant and has a half-life of 32 hours.

See references