Timolol
Istalol is a prescription beta-blocker eye drop used to reduce elevated intraocular pressure in patients with glaucoma or ocular hypertension. The active ingredient timolol works by decreasing the production of fluid in the eye, helping to prevent vision loss associated with increased pressure. It is typically used when other medications are insufficient to control eye pressure.
Istalol is a beta-blocker eye drop that lowers eye pressure to treat glaucoma and ocular hypertension.
Key facts at a glance
- RxNorm
- 542509
- Generic
- Istalol
- Class
- brand-name
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- —
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Istalol is used to treat open-angle glaucoma and ocular hypertension by reducing elevated intraocular pressure when other treatments are inadequate.
As a non-selective beta-blocker, timolol decreases the production of aqueous humor (the fluid inside the eye), thereby lowering intraocular pressure.
Istalol is for topical ophthalmic use only. It may cause systemic beta-blocker effects, particularly in patients with asthma, heart conditions, or diabetes. Patients should wash hands after application and apply pressure to the tear duct to minimize systemic absorption. Do not use while wearing contact lenses unless directed by a doctor. Abrupt discontinuation should be avoided.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy