Brinzolamide (Azopt®)

Overview

Glaucoma is a potentially devastating eye disease, caused by the build-up of abnormally high pressure in the eye. A normal eye produces and drains watery fluid (called aqueous humor). Pressure within the eye builds up if this fluid does not drain properly, and this pressure can damage the optic nerve, leading to vision loss.

Brinzolamide is one of a number of topical medications used to treat glaucoma.

Brinzolamide belongs to a class of drugs called carbonic anhydrase inhibitors (CAI). CAIs decrease the amount of fluid made within the eye by inhibiting the enzyme carbonic anhydrase, which is important in the production of aqueous humor.

Brinzolamide has been introduced relatively recently and has not been extensively studied in animals.

Brinzolamide is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian.

This drug is not approved for use in animals by the Food and Drug Administration (FDA) but it is prescribed legally by veterinarians as an extra-label drug.

Until further studies are published, it should only be used under close monitoring.

Brand Names and Other Names

This drug is registered for humans only. 

Human formulations: Azopt® (Alcon)

Veterinary formulations: None

Uses of Brinzolamide

Based on experience with dorzolamide, a similar drug, brinzolamide has potentially beneficial effects in the treatment of many forms of glaucoma in dogs.

It is not known at this time whether it may also have beneficial effects in the treatment of glaucoma in cats or other animals.

Precautions and Side Effects

While generally safe and effective when prescribed by a veterinarian, brinzolamide can potentially cause side effects in some animals.

Brinzolamide should not be used in animals with known hypersensitivity or allergy to the drug.

Because it is a sulfonamide-type drug, it should not be administered to any animal with a known hypersensitivity to other sulfonamides. Although sulfonamides are primarily antibacterial in nature, brinzolamide has no antibacterial properties.

Brinzolamide and other topical CAIs were developed in an attempt to avoid the potentially serious side effects induced with the oral forms of the CAIs, and so far these topical solutions have been very well tolerated.

Brinzolamide may interact with other medications. Consult your veterinarian to determine if other drugs your pet is receiving could interact with brinzolamide. 

Theoretically, the likelihood of side effects, including metabolic acidosis and excessive loss of potassium may occur when used with other forms of CAIs, so their combined use has been discouraged.

How Brinzolamide Is Supplied

Brinzolamide is available as a 1% solution in 2.5 ml, 5 ml, 10 ml and 15 ml bottles. 

Dosing Information

Medication should never be administered without first consulting your veterinarian.

Brinzolamide should be administered three times daily in dogs with glaucoma. Dosing schedules in cats are yet to be determined.

Because the drug is relatively new, brinzolamide should only be given under the specific direction of a veterinarian.

The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Glaucoma medications must be giving consistently and on a reliable time schedule. Even if your pet feels better, glaucoma medications should not be stopped unless your veterinarian specifically instructs you to do so.