Also known as H168/68, Losec, OMEP, OMP, OMZ, Prilosec

A benzimidazole with selective and irreversible proton pump inhibition activity. Omeprazole forms a stable disulfide bond with the sulfhydryl group of the hydrogen-potassium (H+ – K+) ATPase found on the secretory surface of parietal cells, thereby inhibiting the final transport of hydrogen ions (via exchange with potassium ions) into the gastric lumen and suppressing gastric acid secretion. This agent exhibits no anticholinergic activities and does not antagonize histamine H2 receptors.

Originator: NCI Thesaurus | Source: The website of the National Cancer Institute (http://www.cancer.gov)

Can I take Omeprazole while breastfeeding?

Limited information indicates that maternal omeprazole 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

Maternal Levels. A woman taking oral omeprazole 20 mg daily for gastroesophageal reflux had omeprazole measured in her milk 3 weeks postpartum. The milk omeprazole level 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

Maternal Levels. A woman taking oral omeprazole 20 mg daily for gastroesophageal reflux had omeprazole measured in her milk 3 weeks postpartum. The milk omeprazole level 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.

Possible effects on lactation

A 13-year-old girl was placed on omeprazole 20 mg twice daily by mouth for dyspepsia caused by mefenamic acid and a Helicobacter pylori infection. After 2 days of therapy, she developed bilateral galactorrhea and an elevated serum prolactin. Three weeks after discontinuing omeprazole, galactorrhea and hyperprolactinemia resolved. Six weeks later, she was rechallenged with omeprazole and her serum prolactin rose from 27 to 70 mcg/L. Prolactin returned to normal 2 weeks after omeprazole discontinuation. Over the next 6 months, she was given domperidone on one occasion and lansoprazole on another. With both drugs, she developed galactorrhea and hyperprolactinemia which returned to normal after drug discontinuation.[2]

Alternate drugs to consider

Cimetidine, Famotidine, Nizatidine, Pantoprazole, Ranitidine, Sucralfate

References

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

2. Jabbar A, Khan R, Farrukh SN. Hyperprolactinaemia induced by proton pump inhibitor. J Pak Med Assoc. 2010;60:689-90. PMID: 20726208

Last Revision Date

20150310

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.

Source: LactMed – National Library of Medicine (NLM)

3D Model of the Omeprazole molecule

MolView – data visualization platform