Two medicines, side by side
Timolol vs dorzolamide
Timolol and dorzolamide are both labeled for glaucoma. Drugs@FDA records approvals of timolol since 1978 and of dorzolamide since 1994. Pharmacies paid $0.774 per mL (Timolol maleate 0.5% eye drops) and $0.835 per mL (Dorzolamide HCl 2% eye drops) (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. In FDA's classes, timolol is a beta-adrenergic blocker and dorzolamide a carbonic anhydrase inhibitor.
Check it at the source: the timolol FDA label on DailyMed (effective June 27, 2025); the dorzolamide FDA label on DailyMed (effective June 29, 2026).
Highlights of the timolol record
Timolol (Timoptic) · label of June 27, 2025
Used for
From the label: indicationsBetimol ® is indicated in the treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma.
On the market
- Earliest approval on file
- August 17, 1978
- Generic labelers
- 22 labelers
- Pharmacy cost
- $0.774 per mL
Supply and safety
- Shortage
- No current entry
- Recalls
- 20
Highlights of the dorzolamide record
Dorzolamide (Trusopt) · label of June 29, 2026
Used for
From the label: indicationsDorzolamide hydrochloride ophthalmic solution is indicated in the treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma. Dorzolamide hydrochloride ophthalmic solution is a carbonic anhydrase inhibitor indicated for the treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma.
On the market
- Earliest approval on file
- December 9, 1994
- Generic labelers
- 14 labelers
- Pharmacy cost
- $0.835 per mL
Supply and safety
- Shortage
- No current entry
- Recalls
- 0
Source: FDA drug labels via openFDA (Timolol label of June 27, 2025, Dorzolamide label of June 29, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do timolol and dorzolamide differ on the record?
In FDA's classes, timolol is a beta-adrenergic blocker and dorzolamide a carbonic anhydrase inhibitor.
Generics: timolol since 1989; dorzolamide since 2008 (Drugs@FDA).
| Timolol | Dorzolamide | |
|---|---|---|
| Labeled for | Glaucoma, High blood pressure, Migraine | Glaucoma |
| Pharmacologic class | beta-Adrenergic Blocker | Carbonic Anhydrase Inhibitor |
| How it works (label) | n/a | Carbonic anhydrase (CA) is an enzyme found in many tissues of the body including the eye. It catalyzes the reversible reaction involving the hydration of carbon dioxide and the dehydration of carbonic acid. |
| Half-life (label) | The half-life of timolol in plasma is approximately 4 hours. | n/a |
| Earliest approval on file (Drugs@FDA) | August 17, 1978 | December 9, 1994 |
| First generic approved | April 13, 1989 | October 28, 2008 |
| Generic labelers (NDC) | 22 labelers | 14 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.774 per mL (Timolol maleate 0.5% eye drops) | $0.835 per mL (Dorzolamide HCl 2% eye drops) |
| 12-month price change | -6% | -16% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 20 | 0 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 9,878 | 8,938 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
What next?
- Alternatives to timolol
- every medicine labeled for the same conditions