Brimonidine is a drug used to treat glaucoma. It acts via decreasing aqueous humor synthesis. [Wikipedia] A topical gel formulation, marketed under the name Mirvaso, was FDA approved on August 2013 for the treatment of rosacea. (en)
The ophthalmic solution is indicated for patients with open-angle glaucoma or ocular hypertension to lower intraocular pressure. The topical gel is indicated for the treatment of persistent (nontransient) facial erythema of rosacea in adults 18 years or older. (en)
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. (en)
Oral LD<sub>50</sub> 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. (en)
Minimal systemic absorption occurs after ocular insertion. When the topical gel was applied to adult patients with facial erythema associated with rosacea, the plasma maximum concentration (Cmax) and area under the concentration-time curve (AUC) were 46 ± 62 pg/mL and 417 ± 264 pg.hr/mL, respectively. These values were reached on Day 15 of treatment. (en)