AU: Use is contraindicated during pregnancy and for 1 month prior to conception.
US: This drug is only recommended for use during pregnancy when there are no alternatives and the benefit outweighs the risk to the fetus.

AU TGA pregnancy category: D
US FDA pregnancy category: C

Comments:
-Women of reproductive potential: A negative pregnancy test should be obtained before starting therapy (AU, US) or therapy should be started during the first week of menstruation (AU).
-Effective contraception is recommended during therapy and for 1 month after the last dose; local protocol should be consulted regarding contraception timing.
-If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential harm to the fetus.

Animal studies have revealed evidence of teratogenicity (embryotoxicity and skeletal malformations) in pregnant rats and rabbits. There are no controlled data in human pregnancy.

This drug should not be used in pregnant women except in clinical circumstances where no alternative management is appropriate. Patients should avoid pregnancy until at least 1 month after stopping therapy. If a patient becomes pregnant while taking this drug, it should be discontinued immediately.

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 C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.

See references

This drug and its active metabolites are minimally excreted into breast milk.

Because this drug acts primarily in the intestinal system of the mother and little is absorbed systemically, the WHO considers it compatible with breastfeeding. An informal consultation group concluded single-dose therapy can be used in lactating women.

A single 400 mg oral dose was administered to 33 women who were breastfeeding infants (aged between 2 weeks and 6 months). Milk samples were collected prior to dosing and 6, 12, 24, and 36 hours after dosing. Maternal blood samples were collected 6 hours after dosing. Albendazole, albendazole sulfoxide, and albendazole sulfone were detectable in maternal blood and milk samples. Peak milk level for the sulfoxide metabolite was reached at about 6.9 hours and averaged 352 mcg/L and the half-life in breast milk was 12.4 hours; these properties were determined using data from 20 women who provided at least 3 milk samples. The sulfoxide metabolite level 36 hours after dosing averaged 57 mcg/L; the parent drug and the sulfone metabolite were undetectable (less than 661 mcg/L) in milk at this time. According to author estimation, a fully breastfed infant would be exposed to less than 0.1 mg/kg of the sulfoxide metabolite over the 36 hours after a 400 mg maternal dose and have even less exposure to the parent drug; this correlates to an infant dose less than 1.5% of the weight-adjusted maternal dose.

A single 400 mg oral dose was administered to 2 mothers with intestinal parasites while exclusively breastfeeding their infants (aged between 1 and 6 months). No side effects were reported in the breastfed infants.

LactMed/WHO: Use is considered acceptable.
-AU: Breastfeeding is not recommended during use of this drug and for at least 5 days or at least 1 month after therapy, depending on product.
-US: Caution is recommended.

Excreted into human milk: Yes

Comments: The effects in the nursing infant are unknown.

See references