Is it safe to use pheniramine (antihistamine) and naphazoline (decongestant) eye drops during pregnancy?

Pheniramine and Naphazoline Eye Drops During Pregnancy

Pheniramine and naphazoline eye drops can be used during pregnancy, as pheniramine is the only ophthalmic antihistamine with epidemiologic studies showing no increased risk of congenital malformations, though topical decongestants like naphazoline have limited safety data and oral decongestants should be avoided in the first trimester.

Evidence-Based Recommendation

Pheniramine (Antihistamine Component)

The 2008 Journal of Allergy and Clinical Immunology guidelines specifically state that "the only ophthalmic antihistamine for which epidemiologic studies have been conducted is pheniramine, and there was no reported increase in congenital malformations" 1. This makes pheniramine uniquely positioned among ophthalmic antihistamines with actual human pregnancy data supporting its safety.

A 2019 Danish nationwide cohort study of antazoline-naphazoline eye drops (a similar combination) found no association with major congenital malformations (odds ratio: 0.88,95% CI: 0.71-1.09) among 3,061 exposed pregnancies 2. This large-scale epidemiologic evidence further supports the safety profile of ophthalmic antihistamine-decongestant combinations.

Naphazoline (Decongestant Component)

The evidence for topical decongestants is more limited but reassuring:

• Oral decongestants should be avoided during the first trimester due to conflicting reports linking phenylephrine and pseudoephedrine with gastroschisis and small intestinal atresia 1
• However, the guidelines note that "topical decongestants when used on a short-term basis may have a better safety profile than oral agents for first trimester use" 1
• The key distinction is that topical ophthalmic application results in minimal systemic absorption compared to oral formulations

Clinical Algorithm for Use

First Trimester:

• Pheniramine/naphazoline eye drops can be used if needed for symptomatic relief
• Limit to short-term use when possible
• Avoid combining with oral decongestants, acetaminophen, or salicylates (which may increase malformation risk) 1

Second and Third Trimesters:

• Continue use as needed with the same precautions
• The Danish study showed prescription patterns remained unchanged throughout all trimesters 2

Alternative Considerations:

• If concerned about the decongestant component, consider ophthalmic antihistamines alone
• Intranasal corticosteroids are safe alternatives for allergic symptoms during pregnancy 1
• Sodium cromolyn (Pregnancy Category B) is another safe option 1

Important Caveats

Systemic absorption matters: The safety advantage of ophthalmic formulations over oral decongestants lies in minimal systemic exposure. Proper instillation technique (punctal occlusion after drop administration) can further minimize systemic absorption.

Risk-benefit context: While general antihistamine guidelines recommend avoiding all antihistamines in pregnancy "especially during the first trimester" 3, this conservative stance must be balanced against the specific evidence showing pheniramine's safety in epidemiologic studies and the topical route of administration.

Documentation gap: The guidelines explicitly note that "the data on the safety of topical intranasal decongestants during pregnancy have not been studied" 1, but ophthalmic decongestants would be expected to have even lower systemic exposure than intranasal formulations.