BACKGROUND AND PURPOSE:

• Fexofenadine hydrochloride (trade name Allegra Allergy)
  • H1-receptor antagonist | Over the counter
  • Indicated for relief of symptoms associated with seasonal allergic rhinitis
• Cetirizine hydrochloride (trade name Zyrtec Allergy) and loratadine ( trade name Claritin) are recommended as first-line choice of second-generation antihistamines for use during pregnancy by multiple US and international associations
• Andersson et al. (JAMA Pediatrics, 2020) investigated whether fexofenadine use during pregnancy is associated with an increased risk for adverse fetal outcomes

METHODS:

• Nationwide registry-based cohort study
• Participants
  • Pregnancies in Denmark (January 1, 2001 to December 31, 2016)
• Exposures
  • Filled prescription for fexofenadine
• Study design
  • Pregnancy use of fexofenadine hydrochloride vs cetirizine hydrochloride use were compared
  • Fexofenadine and cetirizine were matched in a 1:1 ratio
  • Sensitivity analyses performed, comparing pregnancies with vs without fexofenadine exposure
  • Also compared fexofenadine exposure with
    • Previous fexofenadine use before pregnancy
    • Loratadine use during pregnancy
• Statistical analysis
  • Logistic regression used to estimate prevalence odds ratios (ORs) of major birth defects, preterm birth, and SGA
  • Cox proportional hazards regression was used to estimate hazard ratios (HRs) of spontaneous abortion and stillbirth
• Primary outcomes
  • Major birth defects
  • Spontaneous abortion
• Secondary outcomes
  • Preterm birth
  • SGA
  • Stillbirth

RESULTS:

• 1,287,668 pregnancies
  • Fexofenadine use: 2962 pregnancies
    • Mean (SD) age for analyses of major birth defects: 30.6 (4.8) years
    • Mean (SD) age for analyses of spontaneous abortion: 30.4 (5.5) years
  • Cetirizine use: 4901 pregnancies
• Fexofenadine use was not associated with an increased risk of major birth defects compared to cetirizine
  • Fexofenadine use: 4.0% (118 pregnancies)
  • Cetirizine use: 3.8% (112 pregnancies)
  • OR 1.06 (95% CI 0.81 to 1.37)
• Fexofenadine use during pregnancy was not associated with an increased risk of spontaneous abortion compared to cetirizine
  • Fexofenadine use: 8.4% (413 pregnancies)
  • Cetirizine use: 9.0% (439 pregnancies)
  • HR 0.93 (95% CI 0.82 to 1.07)
• Fexofenadine use was also not associated with an increased risk of the secondary outcomes
  • Preterm birth
    • Fexofenadine use: 7.5% (370 pregnancies)
    • Cetirizine use: 7.7% (382 pregnancies)
    • OR 0.97 (95% CI 0.83 to 1.12)
  • SGA
    • Fexofenadine use: 10.1% (515 pregnancies)
    • Cetirizine use: 10.2% (523 pregancies)
    • OR 0.98 (95% CI 0.87 to 1.12)
  • Stillbirth
    • Fexofenadine use: 0.3% (16 pregnancies)
    • Cetirizine use: 0.4% (24 pregnancies)
    • HR 0.67 (95% CI 0.36 to 1.27)
• Sensitivity analyses showed similar results (no associations) including comparisons of fexofenadine exposure vs
  • Pregnancies with loratadine use
  • Pregnancies unexposed to fexofenadine during pregnancy but with prior fexofenadine use

CONCLUSION:

• The results of this study did not demonstrate an increased risk of adverse fetal outcomes with fexofenadine use during pregnancy
• The authors state

…we suggest that fexofenadine can be used as equally as the other recommended antihistamines during pregnancy

Learn More – Primary Sources:

Association Between Fexofenadine Use During Pregnancy and Fetal Outcomes

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