Cetirizine is Safe During Breastfeeding
Cetirizine is recommended as a preferred antihistamine during breastfeeding, with extensive safety data showing minimal transfer to breast milk and no reported adverse effects in infants. 1
Guideline-Based Recommendations
The European Respiratory Society explicitly recommends loratadine or cetirizine as preferred antihistamines during breastfeeding, as they have been most extensively studied among second-generation antihistamines. 1
These guidelines represent the highest level of evidence for antihistamine safety during lactation, based on both clinical experience and pharmacokinetic data. 1
Infant Exposure Data
The relative infant dose (RID) of cetirizine is extremely low at 1.77-1.99%, well below the 10% safety threshold used to determine compatibility with breastfeeding. 2, 3
The highest predicted RID occurs at maternal peak concentration (Cmax) and reaches only 3.36%, still well within safe limits. 3
Cetirizine concentrations in breast milk are minimal, with median levels of 13 ng/mL measured in 228 breastfeeding women. 4
Clinical Safety Profile
No adverse effects have been reported in breastfed infants whose mothers used cetirizine. 2
The low milk concentrations and minimal transfer make cetirizine unlikely to pose any significant risk to nursing infants. 2
Population pharmacokinetic modeling confirms that cetirizine is compatible with breastfeeding based on the predicted low infant exposure. 3
Important Caveats
While antihistamines may theoretically reduce milk production, this has not been demonstrated clinically with cetirizine. 1 This theoretical concern should not prevent use when indicated, but mothers should be counseled to monitor milk supply.
In mothers with moderate renal impairment, reduce the cetirizine dose by 50%. 1
Avoid cetirizine entirely in severe renal impairment and consider alternative antihistamines with safer renal profiles. 1
FDA Labeling Discrepancy
The FDA drug label states cetirizine is "not recommended" during breastfeeding. 5 However, this conservative labeling reflects insufficient data at the time of approval rather than evidence of harm.
Current clinical guidelines and recent research supersede this outdated FDA recommendation, with robust evidence now supporting cetirizine safety. 1, 2, 3
This represents a common scenario where manufacturer labeling lags behind clinical evidence—providers should rely on current guidelines rather than package inserts in this case. 1
Practical Algorithm
First-line choice: Use cetirizine or loratadine as preferred second-generation antihistamines for breastfeeding mothers requiring allergy treatment. 1
Assess renal function: Check creatinine clearance if renal impairment is suspected; adjust dose accordingly. 1
Counsel on milk supply: Inform mothers about the theoretical (but unproven) risk of reduced milk production and advise monitoring. 1
Reassure about infant safety: Explain that infant exposure is minimal (<2% of maternal dose) with no reported adverse effects. 2, 3