What allergy medications are safe during pregnancy?

From the Guidelines

Most allergy medications are considered safe during pregnancy, but it's crucial to choose the right ones and consult with a healthcare provider before taking any medication. When it comes to antihistamines, first-generation options like chlorpheniramine and second-generation options like loratadine and cetirizine are generally preferred due to their safety records, as indicated by studies such as 1. Key points to consider include:

• First-generation antihistamines like diphenhydramine and chlorpheniramine are considered safe, with recommended doses of 25-50mg every 4-6 hours for diphenhydramine 1.
• Second-generation antihistamines like loratadine and cetirizine are also safe, typically taken as 10mg once daily 1.
• Nasal steroid sprays such as budesonide are considered safe and can be used as directed on the package.
• Non-medication approaches like avoiding allergens, using saline nasal sprays, and keeping windows closed during high pollen seasons should always be the first line of defense.
• Decongestants like pseudoephedrine should be avoided, especially in the first trimester, due to potential effects on blood flow to the placenta, as noted in 1. It's essential to prioritize caution and consult with a healthcare provider before taking any medication during pregnancy, as individual circumstances may vary, and recommendations can change based on the most recent evidence, such as the guidelines provided in 1 and 1.

From the FDA Drug Label

PREGNANCY Teratogenic Effects Category C There was no evidence of teratogenicity in rats or rabbits at oral doses of terfenadine up to 300 mg/kg (which led to fexofenadine exposures that were approximately 3 and 30 times, respectively, the exposure from the maximum recommended human daily oral dose of fexofenadine hydrochloride of 180 mg based on comparison of AUCs) In mice, no adverse effects and no teratogenic effects during gestation were observed with fexofenadine at dietary doses up to 3730 mg/kg (approximately 15 times the maximum recommended human daily oral dose of fexofenadine hydrochloride 180 mg based on comparison of AUCs). There are no adequate and well controlled studies in pregnant women Fexofenadine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus

Fexofenadine use in pregnancy is categorized as Category C, meaning there are no adequate and well-controlled studies in pregnant women.

• The drug label states that fexofenadine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus 2.
• Therefore, the use of fexofenadine in pregnancy should be approached with caution, and the decision to use it should be made on a case-by-case basis, weighing the potential benefits against the potential risks.

From the Research

Allergy Medicine Safety in Pregnancy

• The safety of allergy medicines during pregnancy is a concern for primary care physicians, as women with pre-existing atopic conditions may require medication changes to avoid potential fetal injury or congenital malformations 3.
• Certain medications are considered relatively safe to continue during pregnancy, including:
  • Intranasal and inhaled steroids, with budesonide being the drug of choice
  • Second-generation antihistamines, such as cetirizine and loratadine
  • Leukotriene receptor antagonists
• However, some medications should be avoided during pregnancy, including:
  • Intranasal antihistamines
  • First-generation antihistamines
  • Mycophenolate mofetil
  • Methotrexate
  • Cyclosporine
  • Azathioprine
  • Zilueton
• The use of oral decongestants during the first trimester should be sparing, and omalizumab may be used for uncontrolled asthma and antihistamine-resistant urticaria 3.

Comparison of Antihistamines

• A study comparing the efficacy of levocetirizine, desloratidine, and fexofenadine found that fexofenadine had the earliest onset of action, while levocetirizine showed maximum inhibition of wheal response after three and six hours 4.
• Another study reviewed the literature on diphenhydramine versus nonsedating antihistamines for acute allergic reactions, finding that newer antihistamines such as loratadine, desloratadine, cetirizine, and fexofenadine are potentially safer and cause less sedation than first-generation antihistamines 5.
• Cetirizine was found to have the fastest onset of action among the newer antihistamines, while fexofenadine did not impair psychomotor or cognitive skills and showed no dose-related increase in sedation 5.