Is cetirizine (antihistamine) safe for infants under 6 months old?

Cetirizine Use in Infants Under 6 Months

Do not give cetirizine drops to infants less than 6 months old—the FDA has not approved any antihistamine for this age group, and safer alternatives exist for managing allergic symptoms. 1

FDA Approval and Age Restrictions

• The FDA-approved cetirizine labeling explicitly states the medication is for patients "6 yrs & older," with no approved dosing for infants under 6 months. 1
• The American Academy of Allergy, Asthma, and Immunology guidelines note that OTC cough and cold preparations recommend consulting a physician for dosing below age 2 years for decongestants and below age 6 years for antihistamines. 2

Safety Concerns in Young Infants

• Between 1969-2006, there were 69 fatalities associated with antihistamines (diphenhydramine, brompheniramine, chlorpheniramine) in children under 6 years, with 41 deaths occurring in children under 2 years. 2
• Drug overdose and toxicity were common events, resulting from use of multiple products, medication errors, accidental exposures, and intentional overdose. 2
• The FDA's Nonprescription Drugs and Pediatric Advisory Committees recommended in 2007 that OTC medications used to treat cough and cold no longer be used for children below 6 years of age due to these safety concerns. 2

Limited Safety Data for Cetirizine in Infants Under 6 Months

• While second-generation antihistamines like cetirizine have been shown to be well tolerated with good safety profiles in young children, the specific evidence supporting use in infants under 6 months is extremely limited. 2
• One randomized, double-blind, placebo-controlled study evaluated cetirizine safety in infants aged 6-11 months (not under 6 months) at 0.25 mg/kg twice daily for 1 week, showing no differences in adverse events compared to placebo. 3
• Most second-generation antihistamines have approval only starting at age 2 years, with some extending down to 6 months in controlled studies—but not below 6 months. 4

Recommended Alternatives for Infants Under 6 Months

First-line treatment:

• Intranasal corticosteroids are the most effective medication class for controlling symptoms of allergic rhinitis in children under 2 years, including all four major symptoms: sneezing, itching, rhinorrhea, and nasal congestion. 4, 2
• When given in recommended doses, intranasal corticosteroids are not generally associated with clinically significant systemic side effects. 4

Adjunctive therapy:

• Isotonic and hypertonic saline solutions can provide modest benefit for reducing symptoms in patients with allergic rhinitis, with minimal side effects, low cost, and generally good patient acceptance. 4

Critical Clinical Pitfall

• Avoid the temptation to extrapolate dosing from older infants (6-11 months) to younger infants (under 6 months). The developmental differences in drug metabolism, hepatic function, and renal clearance in infants under 6 months make this extrapolation potentially dangerous. 3
• The British guidelines recommend avoiding all antihistamines in pregnancy, especially during the first trimester, and note that dosing and age restrictions for individual products vary in younger children, requiring consultation of relevant data sheets before prescribing. 2

When Antihistamine Treatment Becomes Appropriate

• At 6 months of age and older, cetirizine can be administered at 0.25 mg/kg twice daily (approximately 2.5 mg twice daily for a 10 kg infant) based on controlled safety studies. 4, 3
• For children aged 2-5 years, cetirizine can be dosed at 2.5 mg once or twice daily with FDA approval. 4