Is hydroxyzine (an antihistamine) safe to use during pregnancy?

Hydroxyzine Safety During Pregnancy

Hydroxyzine is contraindicated during early pregnancy due to potential fetal abnormalities observed in animal studies and inadequate human safety data for this period. 1

Safety Profile by Trimester

First Trimester

• Hydroxyzine is explicitly contraindicated during early pregnancy according to FDA labeling 1
• Animal studies show fetal abnormalities at doses above the human therapeutic range 1
• Should be used cautiously during the first trimester based on animal data 2
• Alternative antihistamines should be considered for first trimester use

Later Pregnancy

• While the FDA label indicates contraindication in early pregnancy, clinical guidelines suggest cautious use in later trimesters when necessary 3
• When absolutely necessary in later pregnancy, use the lowest effective dose (10-25 mg) with a maximum daily dose of 50 mg 3
• High doses should be avoided as there is a reported case of neonatal withdrawal syndrome with maternal usage of 600 mg daily throughout pregnancy 4

Comparison with Other Antihistamine Options

• First-generation antihistamines like chlorpheniramine have demonstrated safety through long-term use and are often recommended as first-choice agents during pregnancy 2, 3
• Second-generation antihistamines such as cetirizine (which is actually a metabolite of hydroxyzine) and loratadine have better safety profiles confirmed through large birth registries and cohort studies 2, 5
• Cetirizine specifically has been shown not to be associated with increased teratogenic risk in a meta-analysis 5

Special Considerations

• If hydroxyzine is used in the third trimester, newborns should be observed for 48-72 hours after birth for signs of withdrawal 3
• Patients with renal impairment should receive reduced doses or avoid hydroxyzine altogether 3
• Hydroxyzine is also contraindicated in patients with prolonged QT interval 1

Recommendations for Pregnant Women Needing Antihistamines

1. First trimester: Avoid hydroxyzine; use chlorpheniramine, loratadine, or cetirizine instead 2, 3, 1
2. Second and third trimesters: Consider safer alternatives first; if hydroxyzine is necessary, use lowest effective dose (10-25 mg) 3
3. Throughout pregnancy: Avoid combining antihistamines with oral decongestants, especially during the first trimester 2

Monitoring

• Inform pediatricians about maternal hydroxyzine use so they can monitor the newborn for withdrawal symptoms 3
• Monitor for sedation and other side effects in the mother, as hydroxyzine has more pronounced sedative properties than second-generation antihistamines 3

While a 1997 prospective controlled study suggested hydroxyzine may not be associated with increased teratogenic risk 6, the FDA labeling and more recent guidelines still advise caution, particularly in early pregnancy 1. When treating allergic conditions during pregnancy, safer alternatives with more established safety profiles should be prioritized.