Absolute statements for pregnancy and breast feeding are generally not possible due to the limitations in performing double-blind, placebo controlled trials in this vulnerable population. Thus, conclusions are based upon extrapolations from the pharmacology, pharmacokinetics and clinical experience.
There are no specific recommendations stating that cetirizine is safe in pregnancy but there is also no data showing risk. In the prior FDA classification scheme, cetirizine was a Class B drug, no evidence of harm in animal studies but no adequate, randomized, double-blind studies in pregnant women. Guidelines for allergic rhinitis suggest cetirizine for pregnancy when an antihistamine therapy is needed (1). A quote from the 2008 practice parameter on allergic rhinitis is:
“A sufficient amount of human observational data has now been accumulated to demonstrate safety for second-generation as well as first-generation antihistamines.”
There is likewise no controlled data from breast feeding women as to risk to the mother, effects on the infant or impact on breast milk production. Anticholinergic drugs may impact breast milk production via direct acetylcholine inhibition and reduction of glandular secretion, decrease in oxytocin and prolactin production. There is no evidence that the minimal anti-cholinergic effects of cetirizine have any effect on production of breast milk. There is likewise no evidence of negative effects of cetirizine on the breast feeding infant. There is a large, interventional trial using cetirizine 0.5mg/kg/day as a long term treatment starting at 1-2 years of age and no side-effects were documented, including behavioral, cognitive and psychomotor development (2).
In summary, there are no data showing a negative effect of cetirizine in pregnancy or during breast feeding. Limiting medication is preferable but theoretical, unproven risks must be compared to proven efficacy in a shared-decision making discussion.
2. Stevenson, Jim, et al. "Long-term evaluation of the impact of the H1-receptor antagonist cetirizine on the behavioral, cognitive, and psychomotor development of very young children with atopic dermatitis." Pediatric research 52.2 (2002): 251-257. (0.5mg/kg/d long term, no effect)
I hope this information is of help to you and your practice.
All my best.
Dennis K. Ledford, MD, FAAAAI