Levocetirizine Safety During Breastfeeding
Levocetirizine is safe and compatible with breastfeeding, with minimal transfer into breast milk and no significant risk to the infant.
Evidence Supporting Safety
The most recent and highest quality evidence demonstrates that levocetirizine transfer into breast milk is extremely low 1. A 2024 human lactation study specifically measuring levocetirizine concentrations in breast milk found:
- The relative infant dose (RID) was only 1.9%, well below the 10% safety threshold typically used to determine compatibility with breastfeeding 1
- The absolute infant dose was merely 1.1 μg/kg per day, representing negligible exposure 1
- No severe adverse events were reported in breastfed infants 1
Clinical Guidance
All antihistamines, including levocetirizine, are considered safe during breastfeeding because minimal amounts are excreted in breast milk and would not cause adverse effects in breastfeeding infants 2. This is supported by:
- Published studies on second-generation antihistamines like levocetirizine being reassuring regarding safety 2
- Related cetirizine (the racemic mixture containing levocetirizine) showing similarly low milk transfer with a RID of 1.9% 1
Important Caveat Regarding FDA Labeling
The FDA label states levocetirizine is "not recommended" during breastfeeding 3, but this recommendation is outdated and contradicted by current clinical evidence. This discrepancy reflects the common problem where pharmaceutical labeling is overly conservative and does not incorporate recent research demonstrating safety 4.
Special Considerations
- Renal impairment: If the mother has moderate renal impairment, halve the levocetirizine dose; avoid entirely in severe renal impairment 4
- Timing: No specific waiting period before breastfeeding is required after taking levocetirizine 5
- Monitoring: While adverse effects are unlikely, monitor the infant for unusual sedation or irritability as a precaution 6