Questions Concerning the Role of Apraclonidine in the Management of Glaucoma

The studyby Stewart and coworkers1in the March issue of theArchivesis, to my knowledge, the first relatively long-term investigation demonstrating that 0.5% apraclonidine hydrochloride apparently has a role in the long-term therapy for glaucoma. Its use may be appropriate for individuals whose intraocular pressure (IOP) is not sufficiently decreased with a nonselective β-blocker. Apraclonidine (formerly known as ALO 2145,p-aminoclonidine, and aplonidine hydrochloride), like clonidine, is a relatively selective α2-agonist. It differs from clonidine in that an amino group is substituted on the C4position of the benzene ring. This seemingly trivial structural change alters its pharmacologic properties compared with clonidine.2Despite this small chemical change, its IOP-lowering effect remains comparable to that of clonidine. However, there is no compromise in systemic safety or systemic hypotension.3,4This safe IOP lowering opened the door for new uses of the 1% solution.