Dorzolamide Eye Drops in Pregnancy
Dorzolamide can be used during pregnancy when the benefit to the mother justifies the potential fetal risk, but it should be avoided in the first trimester and used with caution thereafter, as it is FDA Pregnancy Category C with demonstrated vertebral malformations in animal studies.
FDA Classification and Animal Data
Dorzolamide is classified as FDA Pregnancy Category C, meaning animal studies have shown adverse effects on the fetus but there are no adequate well-controlled studies in pregnant women 1.
Animal toxicity data: Developmental studies in rabbits at oral doses ≥2.5 mg/kg/day (31 times the recommended human ophthalmic dose) revealed malformations of the vertebral bodies associated with metabolic acidosis, decreased maternal body weight gain, and decreased fetal weights 2.
No malformations occurred at 1.0 mg/kg/day (13 times the human ophthalmic dose) 2.
Clinical Context and Guideline Recommendations
Beta-blockers are generally preferred over dorzolamide during pregnancy because there is long-term clinical experience with this drug class, despite both being Category C 1.
When Dorzolamide May Be Considered:
Late third trimester: Topical carbonic anhydrase inhibitors (including dorzolamide) may be the optimal choice when brimonidine must be discontinued to avoid neonatal CNS depression 3.
Sulfonamide allergy is a contraindication to dorzolamide use 1.
The American Academy of Pediatrics has approved both oral and topical carbonic anhydrase inhibitors during lactation, though careful infant monitoring is required with oral formulations 1.
Risk Mitigation Strategy
If dorzolamide must be used during pregnancy:
Avoid use during the first trimester when organogenesis occurs and teratogenic risk is highest 4.
Use only when IOP control is critical to prevent maternal vision loss and alternative therapies are contraindicated or insufficient 2.
Consider laser trabeculoplasty (ALT or SLT) as an alternative that can be performed safely in all trimesters without fetal drug exposure 3, 5.
Employ techniques to minimize systemic absorption: punctal occlusion, eyelid closure for 2-3 minutes after instillation 5.
Important Caveats
Oral carbonic anhydrase inhibitors (acetazolamide, methazolamide) should be absolutely avoided as they have demonstrated teratogenicity in high doses in animals and carry the same Category C rating with greater systemic exposure 1, 4.
A multidisciplinary approach with obstetrics is essential to balance maternal glaucoma progression risk against fetal safety, as glaucoma treatment should not be withheld when vision loss threatens the mother's quality of life 3, 6, 5.