Brinzolamide
Also known as: Azopt · Azarga
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Glaucoma | 1 drop/eye | topical | q8-12h | — | 🌍 EU |
- Glaucoma: Can be used alone or in combination with other topical drugs.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Glaucoma | 1 drop/eye | topical | q8-12h | — | 🌍 EU |
- Glaucoma: Ineffective in normal cats but may reduce IOP in glaucomatous cats.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Brinzolamide is a topical carbonic anhydrase inhibitor used primarily to control glaucoma in dogs and cats, either alone or in combination with other topical drugs. It is often better tolerated than dorzolamide due to its more physiological pH of 7.5.
Clinical Pearl: While brinzolamide is ineffective at lowering intraocular pressure in normal cats, it can successfully reduce IOP in glaucomatous cats. By contrast, dorzolamide is effective in both normal and glaucomatous cats and dogs.
Mechanism of action
Brinzolamide reduces intraocular pressure (IOP) by inhibiting the enzyme carbonic anhydrase within the ciliary body epithelium.
Inhibition of carbonic anhydrase → decreased formation of bicarbonate ions → reduced fluid transport → decreased rate of aqueous humour production.
Safety & warnings
Contraindications
- Severe hepatic impairment
- Severe renal impairment
- Uveitis (specifically for the timolol combination, as timolol causes miosis)
- Anterior lens luxation (timolol combination)
- Pupil block (timolol combination)
Adverse effects
- Local ocular irritation
- Keratitis
- Blepharitis
- Hypokalaemia (cats, rare systemic effect)
- Metabolic acidosis (dogs, rare systemic effect)
- Bradycardia and hypotension (if using the timolol combination product)
Precautions
Normal ophthalmic handling precautions should be observed.
Warning: Systemic absorption can occur. Rarely, topical carbonic anhydrase inhibitors have been reported to cause hypokalaemia in cats and metabolic acidosis in dogs.
Combination Product Warning: Products containing timolol (a beta-blocker) can cause systemic bradycardia and hypotension, and induce miosis, making them inappropriate for patients with uveitis or anterior lens luxation.
Monitoring
- Intraocular pressure (IOP)
- Signs of local ocular irritation (keratitis, blepharitis)
- Serum potassium and acid-base status (if prolonged use or systemic signs occur)
- Heart rate and blood pressure (if using timolol combination)
Pharmacokinetics
Absorption
Administered topically to the eye, but systemic absorption can occur, potentially leading to systemic side effects (e.g., metabolic acidosis, hypokalaemia).
Overdose
Excessive topical application may increase the risk of systemic absorption, potentially leading to metabolic acidosis or hypokalaemia (especially in cats). If the timolol combination is used, overdose may lead to significant bradycardia and hypotension. Treatment is supportive and symptomatic.
Available products
Formulations
- Ophthalmic drops: 10 mg/ml (1%)
- Ophthalmic drops: 1% brinzolamide + 0.5% timolol
Human-labeled
- Azopt 10 mg/ml (1%) ophthalmic drops in 5 ml bottle
- Azarga 1% brinzolamide + 0.5% timolol ophthalmic drops in 5 ml bottle
Regulatory status
Human registered products used off-label in veterinary medicine under the cascade.
Human registered products (POM) used off-label in veterinary medicine under the cascade.
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store at room temperature. Keep the bottle tightly closed when not in use.
Client information
Administer the exact number of drops prescribed by your veterinarian.
- Wash your hands before and after administration.
- Do not touch the tip of the dropper to the eye or any other surface to prevent contamination.
- If you are applying more than one type of eye medication, wait at least 5-10 minutes between applications.
- Monitor your pet for signs of eye redness, squinting, or rubbing, and contact your veterinarian if these occur or if your pet seems lethargic.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.