Name an alpha-2 adrenergic agonist used in glaucoma and a common side effect.

• A. Brimonidine; conjunctival allergy/erythema and dry mouth
• B. Apraclonidine; dizziness
• C. Timolol; cough
• D. Latanoprost; hyperpigmentation

Answer: (A)

Alpha-2 adrenergic agonists used in glaucoma work by reducing aqueous humor production, and they commonly cause local eye irritation with eye redness (conjunctival allergy/erythema) and can lead to dry mouth from systemic absorption. Brimonidine is a classic alpha-2 agonist for glaucoma, and its most frequently reported adverse effects are conjunctival allergy or erythema and dry mouth, which makes it the best match for the question. The other options belong to different drug classes or have side effects that don’t align as closely with the typical alpha-2 agonist profile: apraclonidine is another alpha-2 drug but is less commonly used long-term and dizziness is less characteristic; timolol is a beta-blocker with systemic effects like bradycardia rather than the noted allergic eye symptoms; latanoprost is a prostaglandin analog whose common issues are conjunctival hyperemia and iris pigmentation rather than allergy or dry mouth.