Brinzolamide with brimonidine

How it works

Brinzolamide inhibits carbonic anhydrase in the ciliary body to reduce aqueous humour formation, while brimonidine both decreases aqueous production and increases uveoscleral outflow, giving additive pressure reduction without a beta-blocker.

Prescribing in practice

• Brimonidine crosses the blood-brain barrier and is contraindicated in neonates and infants because of the risk of apnoea and CNS depression; brinzolamide is a sulfonamide, so avoid in those with sulfonamide hypersensitivity.
• Brinzolamide commonly causes transient blurred vision and a bitter or unusual taste, and brimonidine can cause drowsiness, dry mouth and allergic conjunctivitis.
• Use with caution in significant renal or hepatic impairment and with other systemic carbonic anhydrase inhibitors or CNS depressants.

Monitoring

Monitor intraocular pressure for response and review for sulfonamide-type reactions, ocular allergy and systemic effects such as taste disturbance or drowsiness.

Counselling the patient

• Instil twice daily; shake the bottle and press on the inner corner of the eye after each drop.
• Temporary blurring, a bitter taste, tiredness or a dry mouth may occur.
• Report a red, itchy eye or any rash, and let your clinician know if you are allergic to sulfa medicines.

Evidence & guidelines

This beta-blocker-free fixed combination is supported as an alternative dual therapy in glaucoma where beta-blockade is contraindicated or poorly tolerated.