Animal studies have revealed evidence of developmental toxicity, including teratogenicity and embryolethality. Adverse effects included embryofetal deaths, fetal malformations, reduced skeletal ossification, decreased pup survival, decreased pup weight, and developmental delay. The effects on labor and delivery are unknown. No effect on fertility has been observed. There are no controlled studies 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.

This drug should be used during pregnancy only if the potential benefit justifies the possible risk to the fetus.

US FDA pregnancy category: C

See references

Information from one case report indicate maternal doses of quinidine up to 1.8 grams daily produce low levels in milk and would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months.

Caution is recommended.

Excreted into human milk: Unknown (dextromethorphan); Yes (quinidine)
Excreted into animal milk: Data not available

Comments: The effects in the nursing infant are unknown.

See references