Is hydroxyzine (antihistamine) safe during pregnancy?

From the Guidelines

Hydroxyzine should be used with caution during pregnancy, especially in the first trimester, due to potential risks to the fetus, as indicated by animal studies and the lack of adequate well-controlled studies in humans. The use of hydroxyzine during pregnancy is a concern because it crosses the placental barrier and could potentially affect fetal development, particularly during early pregnancy when organ formation occurs 1. According to the available evidence, first-generation and second-generation antihistamines, in general, have excellent safety records and do not show a significant increase in congenital malformations when used during the first trimester, but caution is still advised for a few antihistamines, including hydroxyzine 1.

Some key points to consider when evaluating the safety of hydroxyzine during pregnancy include:

• The first trimester is the most critical time for concern about potential congenital malformation because of medication use, as this is when organogenesis is occurring 1.
• Hydroxyzine is classified as FDA pregnancy category C, meaning that animal studies have shown adverse effects on the fetus, and there are no adequate well-controlled studies in humans 1.
• Other antihistamines, such as loratadine or cetirizine, have better safety profiles during pregnancy and may be considered as alternatives to hydroxyzine 1.
• If hydroxyzine is necessary during pregnancy, it is essential to discuss the potential risks and benefits with a healthcare provider and to monitor the fetus closely for any potential adverse effects 1.

In terms of management, if you're pregnant and considering hydroxyzine for anxiety, allergies, or itching, it's crucial to discuss safer alternatives with your healthcare provider. For anxiety during pregnancy, non-medication approaches like cognitive behavioral therapy may be preferable, or if medication is necessary, certain SSRIs are often considered safer options. For allergies or itching, other antihistamines like loratadine or cetirizine have better safety profiles during pregnancy 1.

From the FDA Drug Label

Oral hydroxyzine hydrochloride is contraindicated in patients with known hypersensitivity to hydroxyzine hydrochloride products, and in patients with known hypersensitivity to cetirizine hydrochloride or levocetirizine hydrochloride. Hydroxyzine is contraindicated in patients with a prolonged QT interval. Hydroxyzine, when administered to the pregnant mouse, rat, and rabbit induced fetal abnormalities in the rat and mouse at doses substantially above the human therapeutic range. Clinical data in human beings are inadequate to establish safety in early pregnancy. Until such data are available, hydroxyzine is contraindicated in early pregnancy.

• Key points:
  • Hydroxyzine is contraindicated in early pregnancy due to inadequate clinical data to establish safety.
  • Fetal abnormalities were induced in animal studies at doses above the human therapeutic range.
• Hydroxyzine is not safe for use in pregnancy, particularly in early pregnancy, due to the lack of clinical data and potential risks to the fetus 2.

From the Research

Safety of Hydroxyzine in Pregnancy

• The safety of hydroxyzine during pregnancy has been studied in a prospective controlled study published in the Annals of allergy, asthma & immunology 3.
• This study found that the use of hydroxyzine during pregnancy does not appear to be associated with increased teratogenic risk.
• The study compared the pregnancy outcomes of women who took hydroxyzine during pregnancy with those who did not, and found no significant differences in the rates of livebirths, spontaneous or therapeutic abortion, or stillbirth.
• Additionally, there were no differences in the rates of major or minor anomalies, mean birth weight, mode of delivery, gestational age, or presence of neonatal distress.

Comparison with Other Studies

• Another study published in The Cochrane database of systematic reviews 4 examined the efficacy of hydroxyzine in treating generalized anxiety disorder, but did not specifically address its safety during pregnancy.
• This study found that hydroxyzine was more effective than placebo in treating generalized anxiety disorder, but had a higher rate of side effects such as sleepiness and drowsiness compared to other anxiolytic agents.
• However, this study did not provide information on the safety of hydroxyzine during pregnancy, and its findings should not be extrapolated to this population.

Key Findings

• The available evidence suggests that hydroxyzine is not associated with increased teratogenic risk during pregnancy 3.
• However, more research is needed to fully understand the safety of hydroxyzine during pregnancy, and women who are pregnant or planning to become pregnant should consult with their healthcare provider before taking this medication.