Characterization of Drugs for Treating Glaucoma Which are Prostaglandin Analogs with a Stem Name of "-Proston" or "-Prost"

Abstract

Many drugs for glaucoma treatment have recently been developed, but prostaglandin (PG) analogs, which are PGF2α derivatives, are used most frequently. In particular, PG analogs with a stem name of "-prost" have become first-line therapies. When using PG analogs, it is important to understand their chemical structures and characteristics. These PG analogs are biologically active in carboxylate forms and are formulated as prodrugs by esterifying the terminal carboxyl to reduce side effects. The effect of PG analogs on glaucoma is determined by the degree of affinity to prostaglandin FP receptors. the structural formulae of PG analogs and our experimental results suggest that a 15-difluoro PG analog (tafluprost), which has a 13, 14 double bond, would have greater affinity for prostaglandin FP receptors and greater stability than 15-hydroxy PG analogs. Furthermore, 15-difluoro PG analogs containing a 13, 14 double bond were effective in clinical studies. Experimental results have shown that 15-difluoro PG analogs could help improve blood flow in the eye and might reduce the side effect of pigmentation. Tafluprost has been considered the best PG analog for first-line therapy, but a series of new glaucoma eye drops containing 2 active ingredients were launched in Japan in 2010. Each eye drop has advantages and disadvantages, and further studies are necessary to evaluate their clinical usefulness.