Is cetirizine (antihistamine) allowed in neonates (newborns)?

Cetirizine is NOT Approved for Use in Neonates

Cetirizine should not be used in neonates (newborns 0-28 days of age) due to lack of safety data, FDA approval restrictions, and significant safety concerns documented in very young infants. The youngest age at which cetirizine has been studied in controlled trials is 6 months, and even then, only under specific research protocols 1, 2.

FDA Approval and Age Restrictions

• Cetirizine is FDA-approved only for children 6 months and older in the United States, with the over-the-counter formulation labeled for ages 6 years and older 3.
• Most second-generation antihistamines, including cetirizine, have approval starting at age 2 years, with some extending down to 6 months in controlled studies—but never below 6 months 1, 2.
• 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.

Critical Safety Concerns in Young Infants

• Between 1969-2006, there were 69 fatalities associated with antihistamines in children under 6 years, with 41 deaths occurring specifically in children under 2 years due to drug overdose and toxicity 2, 4.
• The FDA's Nonprescription Drugs and Pediatric Advisory Committees recommended in 2007 that OTC medications used to treat cough and cold symptoms no longer be used for children below 6 years of age due to these safety concerns 2, 4.
• There is no safety data for cetirizine use in neonates (0-28 days), as the youngest infants studied were 6-11 months old 5.

When Cetirizine 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 1, 2, 5.
• The first randomized, double-blind, placebo-controlled study of cetirizine in infants aged 6-11 months demonstrated safety with a mean daily dose of 4.5 mg, showing no differences in adverse events compared to placebo and no cardiac QT interval prolongation 5.
• For children aged 2-5 years, cetirizine can be dosed at 2.5 mg once or twice daily with full FDA approval 1, 4.

Recommended Alternatives for Neonates with Allergic Symptoms

If a neonate presents with symptoms suggestive of allergy:

• Focus on identifying and avoiding triggers rather than pharmacotherapy, as antihistamines are contraindicated in this age group 4.
• Immediate referral to a pediatric allergist is indicated if symptoms are severe enough to warrant treatment, rather than empiric antihistamine use 4.
• Saline irrigation (isotonic or hypertonic solutions) can provide modest benefit with minimal side effects and may be considered as supportive care 1.

Critical Clinical Pitfall to Avoid

• Never use first-generation antihistamines (diphenhydramine, hydroxyzine) in neonates or young infants, as these carry even higher risks, with diphenhydramine responsible for 33 of the 69 antihistamine-related deaths in children under 6 years 4.
• Do not use antihistamines "to make a child sleepy"—this is explicitly contraindicated per FDA labeling 4.
• Antihistamines should NOT be administered to infants with atopic dermatitis for prevention of wheezing or asthma, as the risk of side effects outweighs uncertain preventive benefits 4.

Special Considerations for Renal Impairment

• If an infant reaches appropriate age for cetirizine use (≥6 months) but has renal impairment, dose reduction is required in moderate renal impairment, and cetirizine should be avoided in severe renal impairment 2.