Brimonidine is an alpha adrenergic receptor agonist (primarily alpha-2). It has a peak ocular hypotensive effect occurring at two hours post-dosing. Fluorophotometric studies in animals and humans suggest that Brimonidine has a dual mechanism of action by reducing aqueous humor production and increasing uveoscleral outflow. The topical gel reduces erythema through direct vasocontriction.
Brimonidine significantly lowers intraocular pressure with minimal effects on cardiovascular and pulmonary parameters. It lowers intraocular pressure by reducing aqueous humor production and increasing uveoscleral outflow.
Metabolized primarily by the liver.
Oral LD50 is 50 mg/kg in mice and 100 mg/kg in rats. Common adverse reactions of the topical gel formulation include erythema, flushing, skin burning sensation, and contact dermatitis.