The limited information available about the use of omeprazole during breastfeeding indicates that the standard dose of 20 mg/day of this drug reaches a low concentration in milk and not likely to cause adverse effects on the baby. It is considered that, at this dose, the infant could receive a maximum of 1% of the amount given to the mother, being the infant therapeutic dose of 1 mg/kg/ day. There are no published observations about omeprazole adverse effects or systematic monitoring of exposed infants to the drug through breast milk.
Warning of the manufacturer:
Animal studies have shown no evidence of fetal toxicity or teratogenic effects. However, omeprazole, like most medications, should not be administered during pregnancy and lactation, unless its use is deemed essential. The administration of doses up to 80 mg in 24 hours to women during labor has not revealed any adverse effects of omeprazole on the newborn.