Omeprazole Safety During Breastfeeding
Omeprazole is safe to use while breastfeeding, as it passes into breast milk in minimal amounts that are not clinically significant for the infant. 1
FDA-Approved Labeling Position
The FDA label explicitly states that limited data suggest omeprazole may be present in human milk, and recommends that the developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for omeprazole 1. Importantly, the label does not contraindicate breastfeeding while taking omeprazole, but rather advises weighing benefits against any potential adverse effects 1.
Evidence of Minimal Infant Exposure
Pharmacokinetic Data Supporting Safety
Peak omeprazole concentrations in breast milk reach only 58 nM (approximately 7% of peak maternal serum concentration of 950 nM), indicating minimal secretion into breast milk 2
The calculated daily infant dose through breast milk is extremely low at 0.003 mg/kg/day, which is clinically insignificant 3
Esomeprazole (the S-isomer of omeprazole) concentrations in breast milk peaked at 19.6 ng/mL at 4 hours post-dose and became undetectable by 10 hours, with no drug detected in the infant's serum 3
Clinical Outcomes in Breastfed Infants
A case report of a mother taking 20 mg/day omeprazole while breastfeeding showed no adverse effects in the infant, with normal developmental progress 2
An infant exposed to esomeprazole through breast milk demonstrated normal developmental progress with no detectable drug-related adverse effects 3
Practical Clinical Approach
When to Use Omeprazole
Omeprazole is appropriate for lactating women with refractory gastroesophageal reflux disease when other medications (such as ranitidine) have failed 2
The general principle that the risk of drug therapy should be weighed against the risk of untreated maternal symptoms applies here 4
Counseling Points
Women should not be discouraged from breastfeeding while taking omeprazole, given the substantial benefits of breastfeeding for both infant and maternal health 4
The mother can continue breastfeeding without interruption or need to pump and discard milk 2, 3
No special timing of doses relative to breastfeeding is necessary given the minimal transfer into milk 2
Important Caveats
While omeprazole appears safe based on available data, the FDA notes that clinical data on effects in breastfed infants remain limited 1
The evidence base consists primarily of case reports and small studies rather than large-scale trials 2, 3
Physicians should use the most accurate and up-to-date sources of information when counseling mothers about medication use during lactation 5