Brinzolamide with timolol

How it works

Brinzolamide reduces aqueous humour production by inhibiting ciliary-body carbonic anhydrase, while timolol further suppresses aqueous secretion through beta-blockade, producing additive intraocular pressure lowering.

Prescribing in practice

• Because of the timolol component, avoid in asthma, bronchospasm, severe COPD, sinus bradycardia, heart block and uncontrolled heart failure, and counsel on systemic beta-blocker effects.
• Brinzolamide is a sulfonamide derivative, so avoid in patients with sulfonamide hypersensitivity, and expect transient blurred vision and a bitter taste after instillation.
• Use cautiously in marked renal or hepatic impairment, advise punctal occlusion, and remove contact lenses before instillation.

Monitoring

Monitor intraocular pressure for efficacy and assess for sulfonamide reactions and, in susceptible patients, heart rate and respiratory tolerance.

Counselling the patient

• Instil twice daily; shake well and press on the inner corner of the eye afterwards.
• Brief blurred vision and a bitter taste are common after each dose.
• Report breathing difficulty, wheeze or a slow heartbeat, and mention any sulfa allergy.

Evidence & guidelines

NICE glaucoma guidance supports fixed carbonic anhydrase inhibitor/beta-blocker combinations to enhance pressure control and adherence when monotherapy is inadequate.