Acyclovir and breast feeding
Even with the highest maternal dosages, the dosage of acyclovir in milk is only about 1% of a typical infant dosage and would not be expected to cause any adverse effects in breastfed infants. Topical acyclovir applied to small areas of the mother's body away from the breast should pose no risk to the infant. Only water-miscible cream or gel products should be applied to the breast because ointments may expose the infant to high levels of mineral paraffins via licking.
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Alternative drugs - Acyclovir and breast feeding
Suggested alternatives on Acyclovir and breast feeding, when available and appropriate.
Breast feeding and drugs