Levocetirizine Use During Breastfeeding
Levocetirizine is safe to use during breastfeeding, with minimal transfer into breast milk and no reported adverse effects in nursing infants. 1
Evidence Supporting Safety
The most recent and highest quality evidence comes from a 2024 human lactation study that directly measured levocetirizine concentrations in breast milk. This study demonstrated:
- The relative infant dose (RID) for levocetirizine is only 1.9%, well below the 10% safety threshold used to determine compatibility with breastfeeding 1
- The absolute infant dose is approximately 1.1 μg/kg per day, which represents minimal exposure 1
- No severe adverse events were reported in breastfed infants whose mothers used levocetirizine 1
- The study concluded that levocetirizine transfer into breast milk is low and compatible with breastfeeding 1
FDA Labeling Consideration
The FDA drug label for levocetirizine states "not recommended" for breastfeeding 2. However, this conservative labeling does not reflect the current clinical evidence and is common for medications lacking extensive manufacturer-sponsored lactation studies at the time of approval.
Clinical Consensus
Multiple sources confirm antihistamine safety during lactation:
- All antihistamines are considered safe during breastfeeding because minimal amounts are excreted in breast milk and would not cause adverse effects on nursing infants 3
- Most commonly used drugs, including antihistamines, are relatively safe for breastfed babies, with doses received via milk being much smaller than known safe doses given directly to infants 4
Practical Recommendations
To minimize infant exposure further (though already very low):
- Take levocetirizine immediately after breastfeeding rather than before 5
- Use the lowest effective dose 5
- Monitor the infant for potential effects such as irritability or drowsiness, though these are unlikely given the low transfer 5
Important Caveats
- Avoid combination products containing decongestants, as these may have different safety profiles and can potentially reduce milk supply 5
- The cetirizine parent compound has even more extensive safety data in breastfeeding (RID of 1.9% with 31 women studied), making it an equally safe alternative if preferred 1