Cosopt Is a Prescription Eye Drop That Lowers Eye Pressure by Combining Two Medications — Dorzolamide and Timolol — in a Single Drop

If your doctor has prescribed Cosopt or you've seen it mentioned as a treatment for glaucoma, you probably have questions. What exactly is it? How does it work? What will it cost you? This guide covers everything you need to know about Cosopt in 2026, written in plain language.

What Is Cosopt?

Cosopt is the brand name for a combination eye drop containing two active ingredients:

• Dorzolamide 2% — a carbonic anhydrase inhibitor
• Timolol 0.5% — a non-selective beta-blocker

The generic name is Dorzolamide/Timolol (sometimes written as Dorzolamide Hydrochloride and Timolol Maleate). It's manufactured by Merck, and generic versions are made by several manufacturers.

Cosopt was approved by the FDA to treat elevated intraocular pressure (IOP). It's not a controlled substance and does not require any special prescribing procedures.

The medication comes in two formulations:

• Cosopt — standard ophthalmic solution in a 10 mL multi-dose bottle (contains benzalkonium chloride as a preservative)
• Cosopt PF — preservative-free version that comes in single-use vials, designed for patients sensitive to preservatives

What Is Cosopt Used For?

Cosopt is prescribed to lower intraocular pressure (IOP) — the pressure inside your eye. High eye pressure is the main risk factor for glaucoma, a condition that damages the optic nerve and can lead to permanent vision loss if untreated.

Specifically, Cosopt is FDA-approved for:

• Open-angle glaucoma — the most common form of glaucoma, where the eye's drainage angle is open but doesn't drain fluid efficiently
• Ocular hypertension — elevated eye pressure without optic nerve damage (yet), especially in patients who don't respond well enough to a beta-blocker alone

Cosopt is typically prescribed when a single medication isn't enough to control your eye pressure. Instead of using two separate eye drops, Cosopt combines them into one — which is more convenient and improves adherence.

For more on how the two ingredients work together, see our article on how Cosopt works.

How Is Cosopt Taken?

Cosopt is used as follows:

• Dose: One drop in the affected eye(s) twice daily
• Timing: Usually morning and evening, approximately 12 hours apart

Step-by-Step Instructions

1. Wash your hands thoroughly.
2. Tilt your head back and look up.
3. Pull down your lower eyelid gently to create a small pocket.
4. Hold the dropper above your eye and squeeze one drop into the pocket. Don't let the tip touch your eye.
5. Close your eye gently (don't squeeze it shut).
6. Press gently on the inner corner of your eye near your nose (punctal occlusion) for 1 to 2 minutes. This reduces drainage into your throat and minimizes side effects like bitter taste.
7. If you need drops in both eyes, repeat for the other eye.

If you use other eye drops, wait at least 10 minutes between each medication to prevent dilution.

For more about what side effects to watch for, read our guide on Cosopt side effects.

Who Should Not Take Cosopt?

Cosopt is not safe for everyone. You should not use Cosopt if you have:

• Bronchial asthma or a history of asthma
• Severe COPD (chronic obstructive pulmonary disease)
• Sinus bradycardia (very slow heart rate)
• Second- or third-degree heart block
• Overt heart failure or cardiogenic shock
• Allergy to sulfonamides (sulfa drugs), Dorzolamide, Timolol, or any ingredient in Cosopt

You should also use Cosopt with caution if you have:

• Kidney problems (severe renal impairment with creatinine clearance below 30 mL/min)
• Liver disease
• Diabetes (beta-blockers can mask symptoms of low blood sugar)
• A history of depression

Tell your doctor about all your health conditions and medications before starting Cosopt. For a detailed list of medications that interact with Cosopt, see our article on Cosopt drug interactions.

Pregnancy and Breastfeeding

Cosopt is classified as Pregnancy Category C. It should only be used during pregnancy if the benefit clearly outweighs the potential risk. Timolol can pass into breast milk, so breastfeeding while using Cosopt is generally not recommended.

How Much Does Cosopt Cost?

The cost of Cosopt varies significantly depending on whether you get the brand or generic version:

• Brand-name Cosopt: $140 to $220 for a 10 mL bottle
• Generic Dorzolamide/Timolol (retail): $30 to $80 without insurance
• Generic with discount coupon: As low as $10 to $25 through GoodRx, SingleCare, or other discount programs

The generic is on most insurance formularies as a Tier 1 or Tier 2 preferred generic, meaning it will have the lowest copay. Most Medicare Part D plans also cover it.

Brand-name Cosopt and Cosopt PF may require prior authorization or have higher copays.

For more ways to lower your costs, check out our guide on how to save money on Cosopt.

Final Thoughts

Cosopt is a well-established, effective combination eye drop for managing glaucoma and ocular hypertension. It combines two proven medications into one convenient drop, taken just twice a day. The generic version is widely available and affordable — often under $25 with a discount coupon.

The most important things to remember: use it consistently as prescribed, practice proper drop technique, tell your doctor about all your health conditions (especially asthma and heart problems), and keep your follow-up appointments to monitor your eye pressure.

Need to fill your prescription? Search Medfinder to find a pharmacy with Cosopt in stock near you.