Dorzolamide + Timolol Combination

This is a fixed-dose combination eye drop used to lower intraocular pressure (IOP) in people with glaucoma or ocular hypertension.

Components and Their Roles

1. Dorzolamide

   • Type: Carbonic anhydrase inhibitor

   • Action: Reduces the production of aqueous humor (the clear fluid in the eye).

   • Purpose: Lowers IOP by decreasing the amount of fluid made inside the eye.

2. Timolol

   • Type: Non-selective beta-blocker

   • Action: Also reduces aqueous humor production, but through a different mechanism.

   • Purpose: Further lowers IOP, making the combination more effective.

How They Work Together

• Both drugs reduce fluid production in the eye but through different biological pathways.

• This dual action helps achieve greater and more consistent pressure reduction than either drug alone.

Common Uses

• Primary open-angle glaucoma (the most common type)

• Ocular hypertension (when eye pressure is too high but no nerve damage yet)

• Used when a single medication isn’t enough to control eye pressure

Advantages

• More effective than using just dorzolamide or timolol alone

• Convenient — only one bottle to use, usually twice daily

• Helps improve patient compliance with treatment

Possible Side Effects

Eye-related:

• Burning or stinging after instillation

• Bitter taste in the mouth (common with dorzolamide)

• Blurred vision or discomfort

Body-related (mainly from timolol):

• Slow heart rate

• Low blood pressure

• Fatigue

• May worsen asthma, COPD, or certain heart conditions in sensitive patients

Precautions

• Use exactly as prescribed, usually one drop in the affected eye(s) twice daily.

• Press gently on the inner corner of the eye for 1–2 minutes after applying (to reduce systemic absorption).

• Tell your doctor if you have asthma, chronic lung disease, slow heart rate, or heart problems before using.

• If using other eye drops, wait at least 5 minutes between applications.