What allergy medication can a pregnant patient with allergies take?

Safe Allergy Medications During Pregnancy

For pregnant patients with allergies, loratadine and cetirizine are the preferred oral antihistamines, and intranasal budesonide is the first-line nasal corticosteroid, all with extensive human safety data showing no increased risk of congenital malformations. 1, 2

First-Line Oral Antihistamines

Loratadine and cetirizine are the second-generation antihistamines of choice during pregnancy. 1 These medications:

• Have accumulated sufficient human observational data demonstrating safety throughout all trimesters, including over 200,000 first-trimester exposures for first-generation antihistamines and 2,147 exposures for loratadine specifically 1, 3, 4
• Are classified as FDA Pregnancy Category B with no evidence of harm to the fetus 2, 3
• Lack the sedative and anticholinergic properties of first-generation antihistamines, making them superior choices 2

First-Line Intranasal Therapy

Intranasal budesonide is the preferred corticosteroid during pregnancy. 1, 2 This recommendation is based on:

• FDA Pregnancy Category B classification with extensive human safety data 1, 2
• Minimal systemic absorption at recommended doses, reducing fetal exposure 1
• Superior efficacy compared to oral antihistamines for nasal symptoms 1, 5
• A recent meta-analysis showing no increased risk of major malformations, preterm delivery, low birth weight, or pregnancy-induced hypertension 1

While other intranasal corticosteroids (beclomethasone, fluticasone propionate) have reassuring safety data, budesonide has the most accumulated human evidence and should be preferred when initiating therapy during pregnancy 1, 2

Alternative Safe Options

Sodium cromolyn nasal spray is safe but requires frequent dosing and has reduced efficacy. 1 It is:

• FDA Pregnancy Category B with reassuring human and animal data 1
• Appropriate for patients preferring non-corticosteroid options 6, 4
• Limited by the need for 4-6 times daily dosing 6

Montelukast can be used, particularly for patients with coexisting asthma or favorable pre-pregnancy response. 1 Evidence includes:

• FDA Pregnancy Category B classification 1
• Reassuring animal reproductive studies and unpublished human safety data 1
• Minimal data available specifically for pregnancy use, making it a second-line option 1

Critical Medications to Avoid

Oral decongestants (pseudoephedrine, phenylephrine) must be avoided during the first trimester. 1, 2 The rationale:

• Conflicting reports associate these medications with gastroschisis and small intestinal atresia 1, 5
• Risk increases when combined with acetaminophen or salicylates 1
• If decongestants are absolutely necessary after the first trimester, topical intranasal decongestants used short-term may have a better safety profile than oral agents 1

First-generation antihistamines should be used cautiously or avoided during the first trimester. 7 Specifically:

• Hydroxyzine should be avoided based on animal data showing potential risks 1, 7
• Diphenhydramine has older case-control studies suggesting possible association with cleft palate, though evidence is low to moderate 7
• Chlorphenamine has a long safety record but sedating properties make second-generation agents preferable 7, 6

Timing Considerations

The first trimester carries the highest risk for medication-induced congenital malformations due to organogenesis. 1, 2 However:

• All recommended first-line agents (loratadine, cetirizine, intranasal budesonide) have demonstrated safety throughout pregnancy, including the first trimester 2
• After the first trimester, the range of acceptable options expands slightly, though first-line recommendations remain unchanged 1

Allergen Immunotherapy Management

If already established, continue allergen immunotherapy without dose escalation. 1, 5 Key points:

• Women on maintenance immunotherapy can safely continue during pregnancy 1, 5
• Do not increase doses during pregnancy to minimize risk of systemic reactions 1
• Retrospective studies show no increased risk of prematurity, congenital malformations, or perinatal deaths 5
• Do not initiate immunotherapy during pregnancy except in life-threatening cases such as Hymenoptera anaphylaxis 1, 5

Treatment Algorithm

1. Start with intranasal budesonide for nasal symptoms (congestion, rhinorrhea) as the most effective option with excellent safety data 1, 2

2. Add loratadine or cetirizine if additional symptom control needed for sneezing, itching, or systemic symptoms 1, 2

3. Consider sodium cromolyn for patients preferring non-corticosteroid options, accepting reduced efficacy 1

4. Add montelukast for patients with coexisting asthma or inadequate response to above measures 1

5. Avoid oral decongestants entirely in first trimester; consider short-term topical decongestants only after first trimester if absolutely necessary 1, 2

Common Pitfalls to Avoid

• Never prescribe oral decongestants during the first trimester, regardless of symptom severity 1, 2, 5
• Do not combine multiple medications unnecessarily—start with monotherapy and add agents sequentially based on response 2
• Do not discontinue effective allergen immunotherapy if already established, but document benefit-risk assessment 1, 5
• Do not assume all antihistamines have equivalent safety profiles—loratadine and cetirizine have the most robust pregnancy data among second-generation agents 2, 7
• Avoid restricting maternal diet during pregnancy as a strategy for preventing fetal allergy development—this is not recommended 5