Timolol and Dorzolamide/Timolol Interaction
Drug interaction information between Timolol and Dorzolamide/Timolol.
Timolol and Dorzolamide/Timolol have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Timolol and Dorzolamide/Timolol. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Using two medications that both contain timolol can lead to an overdose, which may slow your heart rate down too much or cause low blood pressure.
FDA Label Information
7.7 CYP2D6 Inhibitors Potentiated systemic beta-blockade (e.g., decreased heart rate, depression) has been reported during combined treatment with CYP2D6 inhibitors (e.g., quinidine, SSRIs) and timolol. There have been no reports of exacerbation of rebound hypertension with ophthalmic timolol maleate.
Timolol Also Interacts With
- Dorzolamide moderate
- Clonidine minor
- Brimonidine/Timolol minor
- Darunavir minor
- Verapamil minor
Dorzolamide/Timolol Also Interacts With
- Clonidine minor
- Dorzolamide minor
Frequently Asked Questions
What SPL severity band is on file for Timolol + Dorzolamide/Timolol?
Compiled FDA labeling labels this pair minor. 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/Timolol's 3. In the minor band specifically: Timolol has 5 (also Clonidine, Brimonidine/Timolol, Darunavir, Verapamil); Dorzolamide/Timolol has 3 (also Clonidine, Dorzolamide).
What mechanism field is on file for Timolol and Dorzolamide/Timolol?
Using two medications that both contain timolol can lead to an overdose, which may slow your heart rate down too much or cause low blood pressure.
Timolol's labeled portfolio outnumbers Dorzolamide/Timolol
SPL source-record counts only. This page's band is minor · classes on file: Timolol (Beta-Blocker (Ophthalmic)); Dorzolamide/Timolol (CAI / Beta-Blocker Combination (Ophthalmic)).
0 major · 1 moderate · 5 minor · 6 total
- Other minor peers for Timolol
- Clonidine
- Brimonidine/Timolol
- Darunavir
- Verapamil
0 major · 0 moderate · 3 minor · 3 total
- Other minor peers for Dorzolamide/Timolol
- Clonidine
- Dorzolamide
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.
Read our methodology - how this data is sourced, computed, and verified.