Is levocetrizine (antihistamine) safe to use during breastfeeding?

Levocetirizine Safety During Breastfeeding

Levocetirizine is NOT recommended during breastfeeding according to the FDA drug label, which explicitly states "if breast-feeding: not recommended" 1.

Primary Recommendation

The FDA drug label provides the clearest guidance here and should take precedence as regulatory authority. However, this recommendation appears overly conservative when examined against the most recent clinical evidence.

Evidence-Based Considerations

The most recent 2024 human lactation study demonstrates that levocetirizine transfer into breast milk is extremely low, with a relative infant dose (RID) of only 1.9% and an absolute infant dose of 1.1 μg/kg per day, which the authors conclude is "compatible with breastfeeding" 2. This high-quality pharmacokinetic study directly measured drug concentrations in breast milk from nursing mothers and found:

• Maximum milk concentrations occur approximately 2.4 hours after maternal intake 2
• The half-life in breast milk averages 7.0 hours 2
• No severe adverse events were reported in breastfed infants 2

Clinical Context and Alternative Perspectives

While the FDA label states levocetirizine is "not recommended" during breastfeeding 1, multiple sources provide reassurance:

• All antihistamines are considered safe during breastfeeding as minimal amounts are excreted in breast milk 3
• Recent guidelines on cetirizine (the racemic mixture containing levocetirizine) note that more recent research provides reassurance about its safety during lactation 4

Practical Algorithm for Decision-Making

If levocetirizine is being considered:

1. Check maternal renal function first - avoid if severe renal impairment exists; halve the dose if moderate renal impairment is present 4
2. Counsel on timing - have the mother take medication immediately after breastfeeding to minimize infant exposure 5
3. Use lowest effective dose for shortest duration 5
4. Monitor infant for adverse effects - watch for paradoxical CNS stimulation, drowsiness, or irritability 5

Important Caveats

• The FDA's conservative stance may reflect limited data at the time of labeling rather than evidence of harm 1
• The 2024 lactation study provides the most robust pharmacokinetic data showing safety, but represents only one woman using levocetirizine specifically (though 31 used cetirizine) 2
• Avoid combination products containing alcohol, aspirin, or multiple unnecessary ingredients 5

In real-world clinical practice, given the 2024 evidence showing minimal transfer and no adverse effects, levocetirizine can be used cautiously during breastfeeding when clinically necessary, despite the FDA label's blanket "not recommended" statement 2. The key is informed consent, proper timing of doses, and infant monitoring.