Zileuton Pregnancy and Breastfeeding Warnings

Brand names: Zyflo, Zyflo CR

Medically reviewed by Drugs.com. Last updated on Nov 21, 2023.

Zileuton Pregnancy Warnings

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

US FDA pregnancy category: C

Developmental studies indicated adverse effects (reduced body weight and increased skeletal variations) in rats at an oral dose of 300 mg/kg/day. In rabbits receiving oral dose of 150 mg/kg/day, cleft palates were also reported. This drug and/or its metabolites cross the placental barrier of rats. There are no controlled data in human pregnancy.

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

Zileuton Breastfeeding Warnings

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: The effects in the nursing infant are unknown.

See references

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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