Is Zyrtec (cetirizine) safe to use during pregnancy?

Cetirizine (Zyrtec) Safety During Pregnancy

Cetirizine (Zyrtec) is generally considered safe during pregnancy, classified as FDA Pregnancy Category B, indicating no evidence of harm to the fetus although well-controlled human studies are limited. 1

Safety Profile and Recommendations

• The FDA drug label specifically recommends consulting a healthcare professional before using cetirizine during pregnancy 2
• Cetirizine is classified as a Category B medication, meaning animal studies have not demonstrated risk to the fetus and there are no adequate well-controlled studies in pregnant women 1
• A prospective controlled study specifically examining cetirizine in pregnancy found no significant differences in pregnancy outcomes (including rates of major or minor anomalies, birth weight, gestational age, or neonatal distress) compared to control groups 3

Decision-Making Algorithm for Antihistamine Use in Pregnancy

1. First Trimester Considerations:

   • If possible, avoid all antihistamines during the first trimester 1
   • If treatment is necessary, cetirizine is one of the preferred options due to its Category B classification

2. Second and Third Trimester:

   • Cetirizine can be used when clinically indicated
   • No evidence of increased congenital malformations has been found 1

3. Alternative Options:

   • Chlorphenamine (chlorpheniramine) is often chosen in the UK due to its long safety record 1
   • Loratadine is another Category B option similar to cetirizine 1

Important Precautions

• Avoid oral decongestants if possible during the first trimester due to reports of association with congenital malformations 1
• In patients with renal impairment, the dose of cetirizine should be halved 1
• Hydroxyzine (another antihistamine) is specifically contraindicated during early pregnancy 1

Comparison to Other Antihistamines

• First-generation antihistamines have more sedating effects which may be undesirable during pregnancy
• Second-generation antihistamines like cetirizine have comparable safety data to first-generation options with fewer side effects 1
• For allergic rhinitis during pregnancy, intranasal corticosteroids may be preferred as first-line therapy over oral antihistamines 4

While no medication can be guaranteed 100% safe during pregnancy, the available evidence suggests cetirizine is one of the safer antihistamine options when treatment is necessary during pregnancy. The benefits of treating significant allergic symptoms generally outweigh the potential risks of the medication.