Omeprazole Use During Breastfeeding
Omeprazole is compatible with breastfeeding, as minimal amounts transfer into breast milk and the drug has poor oral bioavailability in infants, making clinically significant effects on the breastfed infant highly unlikely. 1
Evidence Supporting Safety
Drug Transfer and Infant Exposure
Omeprazole concentrations in breast milk are minimal, with peak levels reaching less than 7% of maternal serum concentrations (58 nM in milk versus 950 nM in serum at 3-4 hours post-dose). 2
The calculated daily infant dose through breast milk is negligible, estimated at approximately 0.003 mg/kg/day for esomeprazole (the S-isomer of omeprazole), which represents a clinically insignificant exposure. 3
Esomeprazole (closely related to omeprazole) is undetectable in infant serum when measured 12 hours after delivery, and breast milk levels become undetectable by 10 hours after maternal administration. 3
FDA Labeling Guidance
The FDA label acknowledges that limited data suggest omeprazole may be present in human milk, but emphasizes that the developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for the medication. 1
No specific contraindication exists for breastfeeding while taking omeprazole, and mothers are advised to discuss feeding options with their healthcare provider. 1
Clinical Considerations
Pharmacokinetic Advantages
Proton pump inhibitors like omeprazole have poor oral bioavailability in infants due to acid degradation in the infant's stomach, further reducing any potential systemic effects from the small amounts present in breast milk. 2
The drug's pharmacokinetic profile supports safety, as it is rapidly metabolized and has minimal transfer into milk relative to maternal dosing. 2, 3
Real-World Evidence
Case reports demonstrate no adverse effects in breastfed infants whose mothers took omeprazole 20 mg daily, with infants showing normal developmental progress and no drug-related complications. 2, 3
Historical use patterns support compatibility, as omeprazole has been used during lactation without documented harm to infants when standard therapeutic doses are employed. 4, 5
Practical Recommendations
Continue breastfeeding while taking omeprazole at standard therapeutic doses (typically 20-40 mg daily), as infant exposure is negligible. 1, 2
Monitor the infant for any unusual symptoms such as excessive sleepiness, feeding difficulties, or gastrointestinal changes, though these are not expected based on the pharmacokinetic data. 3
No need to pump and discard milk or time feedings around medication administration, as the drug levels in milk remain consistently low throughout the dosing interval. 2, 3
Alternative H2 antagonists (famotidine, nizatidine) may be considered if there are concerns, though omeprazole itself is acceptable and often more effective for acid suppression. 5