Is cetirizine (antihistamine) safe to use during breastfeeding?

Cetirizine Safety During Breastfeeding

Cetirizine is safe to use during breastfeeding with minimal transfer to breast milk and low risk to the breastfed infant. Despite the FDA label recommending against its use during breastfeeding 1, recent research strongly supports its safety.

Evidence for Safety

• Recent human lactation studies show cetirizine transfers minimally into breast milk:

  • Relative infant dose (RID) is only 1.77-1.99% 2, 3
  • Maximum RID reported is 3.36% at peak concentration 3
  • Well below the 10% threshold generally considered safe for breastfeeding

• A 2024 study of 32 breastfeeding women found:

  • Mean maximum cetirizine milk concentration was 41.0 μg/L
  • Average concentration was only 16.8 μg/L
  • No severe adverse events were reported in infants 4

Pharmacokinetic Considerations

• Cetirizine reaches maximum concentration in milk approximately 2.4 hours after intake 4
• Mean half-life in milk is about 7.0 hours 4
• The estimated absolute infant dose is very low at 2.5 μg/kg/day 4

Clinical Recommendations

1. Timing considerations:

   • For minimal infant exposure, take cetirizine immediately after breastfeeding to maximize clearance time before the next feeding

2. Monitoring:

   • Watch for potential mild sedation in the infant, though this is rarely reported
   • Extra caution with infants less than 6 weeks old due to immature hepatic and renal function

3. Dosing:

   • Standard adult dosing is appropriate
   • No special dosage adjustment needed for lactation

Important Caveats

• The FDA label currently does not recommend cetirizine during breastfeeding 1, but this appears to be due to insufficient data at the time of labeling rather than evidence of harm
• Cetirizine should be used with caution in mothers with severe renal impairment (creatinine clearance <10 mL/min) 5
• If concerned about sedation, non-sedating second-generation antihistamines like cetirizine are preferred over first-generation antihistamines

Alternative Options

If cetirizine is not suitable, loratadine is another well-studied antihistamine during breastfeeding with similar safety profile 5, 6.

In conclusion, the benefits of treating allergic symptoms in a breastfeeding mother with cetirizine outweigh the minimal risk of medication exposure to the infant through breast milk.