Brimonidine

Brimonidine is a medication used in both ophthalmology and dermatology. In ophthalmology, it is a selective alpha-2 adrenergic receptor agonist that lowers intraocular pressure by decreasing aqueous humor production and, to a lesser extent, increasing uveoscleral outflow. It is indicated for open-angle glaucoma and ocular hypertension and is available as an eye drop in several concentrations, commonly 0.1%, 0.15%, or 0.2% brimonidine tartrate, depending on the market. Fixed-dose combinations include Combigan, which combines brimonidine tartrate 0.2% with timolol maleate 0.5%, and Simbrinza, which pairs brimonidine tartrate with brinzolamide.

In dermatology, brimonidine tartrate 0.5% gel is used to treat facial erythema of rosacea under brand names such as Mirvaso; it acts to cause vasoconstriction locally, reducing redness.

Mechanism and pharmacology: Brimonidine is a selective agonist of alpha-2 adrenergic receptors. In the eye, this reduces aqueous humor production by ciliary body processes and can modestly improve outflow, thereby lowering intraocular pressure. Systemic absorption is limited but can cause hypotension, bradycardia, and drowsiness in susceptible individuals.

Side effects: Common ocular adverse effects include conjunctival hyperemia, dry eye, ocular pruritus, and blurred vision. Systemic effects may include dizziness, fatigue, or headache. Rare but serious events include allergic conjunctivitis and hypotension. Brimonidine should be used with caution in patients with cardiovascular disease, and it is generally avoided in very young children due to central nervous system effects; safety in pregnancy and lactation is not fully established.

Storage and handling: Use as prescribed and store at room temperature; discard after opening as directed by the product label to reduce risk of contamination.