Topical carbonic anhydrase inhibitor Pregnancy: SPC §4.6: there are no or limited data from use of ophthalmic brinzolamide in pregnant women; animal studies have shown reproductive toxicity following systemic administration. Not recommended during pregnancy or in women of childbearing potential not using contraception. Breast-feeding: excretion in human milk unknown, a risk to newborns/infants cannot be excluded — decide whether to discontinue breast-feeding or the medicine.

Brinzolamide

Brand names: Azopt

Brinzolamide is a topical carbonic anhydrase inhibitor used to lower intraocular pressure in open-angle glaucoma and ocular hypertension.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: One drop in the conjunctival sac of the affected eye(s)

Route: Topical ocular (brinzolamide 10 mg/ml eye drops, suspension)

Frequency: Twice daily; some patients may have a better response with one drop three times a day

Max: The dose should not exceed one drop in the affected eye(s) three times daily

SPC §4.2: dose applies when used as monotherapy or as adjunctive therapy. Elderly: no dose adjustment necessary. Shake the bottle well before use; nasolacrimal occlusion or gently closing the eyelid after instillation is recommended to reduce systemic absorption. Remove contact lenses prior to application and wait at least 15 minutes before reinsertion. If more than one topical ophthalmic medicinal product is used, administer at least 5 minutes apart; eye ointments last. When substituting another ophthalmic antiglaucoma agent with brinzolamide, discontinue the other agent and start brinzolamide the following day. If a dose is missed, continue with the next dose as planned. Paediatric: efficacy and safety in infants, children and adolescents aged 0 to 17 years have not been established — not recommended for use in this group. Hepatic impairment: not studied, not recommended. NOTE — US/UK divergence: the US Azopt prescribing information states one drop in the affected eye(s) 3 times daily (with other topical drops ≥10 minutes apart); the UK SPC dose above (twice daily) has been used.

Dose adjustments

Renal

SPC §4.2/§4.3: contraindicated in severe renal impairment. Not studied in patients with severe renal impairment (creatinine clearance <30 ml/min) or in hyperchloraemic acidosis; brinzolamide and its main metabolite are excreted predominantly by the kidney. Use with caution where there is a risk of renal impairment because of the possible risk of metabolic acidosis (§4.4).

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substance or to any of the excipients
Known hypersensitivity to sulfonamides
Severe renal impairment
Hyperchloraemic acidosis

Side effects

Dysgeusia — bitter or unusual taste (6.0%, most frequent treatment-related reaction)
Temporary blurred vision on instillation, lasting seconds to minutes (5.4%)
Eye irritation, eye pain, foreign body sensation in eyes, ocular hyperaemia (common)
Corneal erosion, keratitis, punctate keratitis, blepharitis, eye pruritus, dry eye, conjunctivitis (uncommon)
Dizziness, headache, paraesthesia, motor dysfunction, amnesia (uncommon)
Serious sulfonamide-type reactions including Stevens-Johnson syndrome and toxic epidermal necrolysis (§4.4 — withdraw immediately if they occur)

Interactions

Oral carbonic anhydrase inhibitors — potential additive effect on the systemic effects of carbonic anhydrase inhibition; concomitant administration has not been studied and is not recommended (SPC §4.4 'Concomitant therapy')
High-dose salicylate therapy — rare instances of acid-base alterations have occurred in patients treated with oral carbonic anhydrase inhibitors; the potential for such interaction should be considered (US Azopt label §7.2 — not present in the fetched UK SPC text)
Other topical ophthalmic medicinal products — administer at least 5 minutes apart, eye ointments last (SPC §4.2)

Clinical monograph

How it works

It inhibits carbonic anhydrase in the ciliary epithelium, reducing aqueous humour formation and thereby lowering intraocular pressure.

Prescribing in practice

As a sulfonamide derivative it is contraindicated in patients with known sulfonamide hypersensitivity, and systemic sulfonamide-type reactions can rarely occur.
Avoid in severe renal impairment because of reduced clearance of the active metabolite.
Blurred vision on instillation is common owing to the suspension formulation; shake well before use.

Monitoring

Monitor intraocular pressure response and remain alert for ocular discomfort, altered taste and rare systemic sulfonamide-type hypersensitivity reactions.

Counselling the patient

Shake the bottle well and expect transient blurring after instillation.
Remove soft contact lenses before use and wait before reinserting them.
A temporary bitter or unusual taste in the mouth after dosing is common and harmless.

Evidence & guidelines

Topical carbonic anhydrase inhibitors are a well-established treatment option for reducing intraocular pressure, used alone or as adjunctive therapy.

Reference: NICE NG81; RCOphth; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways