What antiallergic medications are safe to use during pregnancy?

Safe Antiallergic Medications During Pregnancy

Second-generation antihistamines loratadine and cetirizine are the preferred antiallergic medications during pregnancy due to their established safety profiles and efficacy. 1

First-Line Treatment Options

Antihistamines

• Second-generation antihistamines have excellent safety records during pregnancy 1:
  • Loratadine - FDA Pregnancy Category B, well-studied with no evidence of increased congenital malformations 1, 2
  • Cetirizine - FDA Pregnancy Category B, confirmed safety through large birth registries and cohort studies 2, 3
• First-generation antihistamines are generally safe but have undesirable sedative effects 1:
  • Chlorpheniramine has a long safety record and can be used if second-generation options are unavailable 4, 5
  • Diphenhydramine should be used cautiously due to some concern about potential association with cleft palate 1

Intranasal Corticosteroids

• Intranasal corticosteroids are effective and safe for nasal symptoms during pregnancy 1:
  • Budesonide is preferred (FDA Pregnancy Category B) based on extensive human safety data 1, 6
  • Other intranasal corticosteroids (fluticasone, mometasone) can be continued if they adequately controlled symptoms before pregnancy 1, 5
• These medications show minimal systemic absorption when used at recommended doses 1, 5

Other Safe Options

• Sodium cromolyn nasal spray (FDA Pregnancy Category B) is safe but requires frequent dosing (4 times daily) and has reduced efficacy compared to other agents 1, 4
• Montelukast (FDA Pregnancy Category B) can be considered if there was a favorable pre-pregnancy response, though limited human data exists 1

Medications to Avoid or Use with Caution

First Trimester Concerns

• Oral decongestants (pseudoephedrine, phenylephrine) should be avoided during the first trimester due to conflicting reports of association with congenital malformations such as gastroschisis and small intestinal atresia 1
• Risk increases when decongestants are combined with acetaminophen or salicylates 1, 2
• Hydroxyzine should be used cautiously during first trimester based on animal data 1, 2

Limited Safety Data

• Levocetirizine has limited safety data specifically for pregnancy and should be avoided if possible during the first trimester 2
• Desloratadine, azelastine, and fexofenadine have limited human pregnancy data 1

Treatment Algorithm for Allergic Rhinitis in Pregnancy

1. First-line therapy:

   • Intranasal corticosteroids (preferably budesonide) for nasal symptoms 1, 5
   • Second-generation antihistamines (loratadine or cetirizine) for systemic symptoms 1, 7

2. Alternative options if first-line therapy is ineffective:

   • Sodium cromolyn nasal spray 1, 4
   • Montelukast (if previously effective) 1

3. For severe symptoms unresponsive to above treatments:

   • Consider short-term use of intranasal decongestants (after first trimester) 1, 6
   • Allergen immunotherapy may be continued if already established before pregnancy but should not be initiated during pregnancy 1

Important Clinical Considerations

• The first trimester is the most critical period for potential congenital malformations due to medication exposure 1
• Benefit-risk assessment is crucial - untreated severe allergic symptoms can negatively affect maternal and fetal outcomes 7, 5
• Non-pharmacological approaches (allergen avoidance, saline nasal irrigation) should be implemented before or alongside medication 2, 6

Common Pitfalls

• Assuming all antihistamines have equivalent safety profiles during pregnancy 2
• Using oral decongestants during first trimester or in combination with acetaminophen/salicylates 1
• Discontinuing effective pre-pregnancy treatment unnecessarily, which may lead to poor symptom control 1, 5