<p>Brimonidine is an &alpha;-2 adrenoreceptor agonist that is more selective for the &alpha;-2 adrenoreceptor than &alpha;-1. Topical administration of Brimonidine Tartrate eye drops decreases intraocular pressure (IOP) in humans. When used as directed Brimonidine Tartrate have the action of reducing elevated IOP with minimal effect on cardiovascular parametres. Brimonidine Tartrate eye drops have a rapid onset of action with the peak ocular hypotensive effect occurring at two hours post-dosing. The duration of effect is 12 hours or greater. Fluorophotometric studies in animals and humans suggest that Brimonidine Tartrate has a dual mechanism of action. Brimonidine Tartrate eye drops lower IOP by reducing aqueous humor production and enhancing uveoscleral outflow.</p>