Drug Levels and Effects:

Summary of Use during Lactation:

Esomeprazole is the


-enantiomer of the proton-pump inhibitor,omeprazole. Limited information indicates that maternal doses of 20 mg daily produce low levels in milk and would not be expected to cause any adverse effects in breastfed infants.

Drug Levels:

Esomeprazole is the


-isomer ofomeprazole. Information is currently available only for racemicomeprazole. Information is currently available only for racemicomeprazole.

Maternal Levels.

A woman takingomeprazole20 mg orally daily for gastroesophageal reflux hadomeprazolemeasured in her milk 3 weeks postpartum. The milkomeprazolelevel was not detectable for 90 minutes after the dose and then reached a peak of 20 mcg/L at 3 hours after the dose.[1] Using the peak milk level in this patient, the maximum dose that an exclusively breastfed infant would receive in breastmilk would be 3 mcg/kg daily or about 0.9% of the maternal weight-adjusted dosage. For comparison, doses of 1 mg/kg daily have been used in neonates.

Infant Levels.

Relevant published information was not found as of the revision date.

Effects in Breastfed Infants:

One mother takingomeprazole20 mg daily orally pumped and discarded her milk once each day 4 hours after her morning dose. She breastfed her infant the remainder of the day for 3 months before weaning. The infant remained well at 12 months of age.[1]

Possible Effects on Lactation:

Relevant published information was not found as of the revision date.

Alternate Drugs to Consider:



1. Marshall JK, Thompson AB, Armstrong D.Omeprazolefor refractory gastroesophageal reflux disease during pregnancy and lactation. Can J Gastroenterol. 1998;12:225-7. PMID:9582548

Substance Identification:

Substance Name:


CAS Registry Number:


Drug Class:

  • Anti-Ulcer Agents

  • Administrative Information:

    LactMed Record Number:


    Last Revision Date:

    Disclaimer:Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.