Timolol and Dorzolamide Interaction

Drug interaction information between Timolol and Dorzolamide.

Timolol and Dorzolamide have a documented moderate interaction in FDA labeling.

FDA drug labeling documents a moderate-severity interaction between Timolol and Dorzolamide. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.

Drug A

Timolol

Beta-Blocker (Ophthalmic)

Drug B

Dorzolamide

Carbonic Anhydrase Inhibitor (Ophthalmic)

How They Interact

Using these drugs together can cause their effects to stack up, which may lead to more side effects throughout your body.

FDA Label Information

7 DRUG INTERACTIONS Potential additive effect of oral carbonic anhydrase inhibitor with dorzolamide hydrochloride and timolol maleate ophthalmic solution. ( 7.7 ) 7.1 Oral Carbonic Anhydrase Inhibitors There is a potential for an additive effect on the known systemic effects of carbonic anhydrase inhibition in patients receiving an oral carbonic anhydrase inhibitor and dorzolamide hydrochloride and timolol maleate ophthalmic solution. The concomitant administration of dorzolamide hydrochloride and timolol maleate ophthalmic solution and oral carbonic anhydrase inhibitors is not recommended.

Frequently Asked Questions

What SPL severity band is on file for Timolol + Dorzolamide?

Compiled FDA labeling labels this pair moderate. That is a source-record field, not an individual medication-combination decision.

Which drug in this pair has the larger labeled-interaction portfolio?

Timolol has 6 labeled pairs on file vs Dorzolamide's 2. In the moderate band specifically: Timolol has 1; Dorzolamide has 1.

What mechanism field is on file for Timolol and Dorzolamide?

Using these drugs together can cause their effects to stack up, which may lead to more side effects throughout your body.

Timolol's labeled portfolio outnumbers Dorzolamide

SPL source-record counts only. This page's band is moderate · classes on file: Timolol (Beta-Blocker (Ophthalmic)); Dorzolamide (Carbonic Anhydrase Inhibitor (Ophthalmic)).

Timolol

0 major · 1 moderate · 5 minor · 6 total

Timolol has no other moderate-band peer in this dataset besides Dorzolamide.

Dorzolamide

0 major · 1 moderate · 1 minor · 2 total

Dorzolamide has no other moderate-band peer in this dataset besides Timolol.

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.