Brimonidine: a New Alpha2-adrenoreceptor Agonist for Glaucoma Treatment

Purpose: Brimonidine is a highly selective alpha2-adrenoceptor agonist. It has intraocular pressure (IOP)-lowering characteristics similar to other alpha2-agonists and acts by reducing aqueous humor production and increasing uveoscleral outflow. It is oxidatively stable, which may account for its lower reported rate of ocular allergy compared with other alpha2-agonists. The focus of this report is to review the receptor pharmacology and clinical experience with brimonidine tartrate, the newest of the alpha2-adrenergic agonists.

Methods: Clinical studies have been performed for acute indications using the 0.5% concentration and chronic indications using the 0.2% concentration.

Results: Brimonidine 0.5% given as one drop before, after, or both before and after 360 degrees argon laser trabeculoplasty significantly lowers the incidence of postlaser IOP spikes. Brimonidine 0.2% instilled twice daily offers long-term IOP control comparable with that achieved with timolol 0.5% and better than betatolol 0.25% suspension.

Conclusions: In light of these data, brimonidine 0.5% may be considered for prophylaxis against laser-induced IOP spikes and brimonidine 0.2% for chronic use in patients with ocular hypertension and glaucoma.