Brinzolamide
Antiglaucoma agents
Antiglaucoma agents
A carbonic anhydrase inhibitor eye drop that makes less aqueous humour and so lowers eye pressure. It is a sulfonamide and can blur vision briefly.
Quick facts
- Group
- Antiglaucoma agents
- Target
- Carbonic anhydrase II of the ciliary processes
- Used for
- Open-angle glaucoma · Ocular hypertension
- Key effects
- Blurred vision right after the drop · Bitter
- Monitor
- Intraocular pressure · Skin rash or signs of allergy
- ATC
- S01EC04
No doses: the clinician sets them by the current guideline.
Mechanism of action
The figure shows brinzolamide bound to the zinc active site of human carbonic anhydrase II.
Brinzolamide inhibits carbonic anhydrase II in the ciliary processes. Less bicarbonate forms, so less sodium and water are moved into the eye, aqueous humour secretion falls and intraocular pressure drops. Some drug is absorbed and binds the same enzyme in red blood cells, which explains its long stay in whole blood.
- Brinzolamide blocks carbonic anhydrase II in the ciliary body
- Less bicarbonate, less sodium and fluid transport
- Less aqueous humour; intraocular pressure falls
Indications
- Open-angle glaucoma Open-angle glaucoma →
- Ocular hypertension
Adverse effects
Common
- Blurred vision right after the drop (it is a suspension)
- Bitter, sour or unusual taste
- Eye discomfort, itching or redness
Contraindications
- Hypersensitivity to brinzolamide or any component
- Caution in sulfonamide allergy
Key interactions
- Oral carbonic anhydrase inhibitors (acetazolamide)
- Additive systemic effects; the combination is not recommended
- High-dose salicylates
- Rare acid-base disturbances
What is monitored
- Intraocular pressure
- Skin rash or signs of allergy
- Corneal clarity in eyes with endothelial disease
Administration and safety
- Shake the suspension well before each use.
- Other eye drops are spaced at least 10 minutes apart.
- Contact lenses come out before the drop and go back in about 15 minutes later.
Pregnancy and breastfeeding
There are no adequate human studies; it is used in pregnancy only if the benefit justifies the risk.
Nursing care
- Ask about sulfonamide allergy before the first dose.
- Warn about brief blurred vision and a bitter taste.
- Teach to stop and report rash, blistering, eye pain or swelling.
Pharmacokinetics
- Absorption
- Absorbed into the blood from the eye; plasma levels stay low
- Distribution
- Binds carbonic anhydrase in red blood cells and stays there a long time
- Elimination
- Mainly in urine, largely unchanged
Test yourself
Think of the answer, then tap the question to see it.
Which enzyme does brinzolamide inhibit?
Carbonic anhydrase II in the ciliary processes.
Which allergy history matters before starting?
Sulfonamide allergy, because brinzolamide is a sulfonamide.
Why should it not be combined with oral acetazolamide?
The systemic effects of carbonic anhydrase inhibition add up.
Connections
← Back to the class: Antiglaucoma agents
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - BRINZOLAMIDE suspension/ drops (DailyMed (U.S. National Library of Medicine), 2021); Brinzolamide Ophthalmic: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); RCSB PDB - 4M2R: Human Carbonic Anhydrase II in complex with Brinzolamide (RCSB Protein Data Bank, 2026).
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Representative model, for educational purposes only.