CLINICAL EFFICACY OF PHXA34 AND PHXA41, 2 NOVEL PROSTAGLANDIN-F(2-ALPHA)-ISOPROPYL ESTER ANALOGS FOR GLAUCOMA TREATMENT

Four clinical studies were performed in 54 healthy japanese volunteers to assess the efficacy and the safety of two phenyl-substituted PGF2a lpha-isopropyl ester analogues, PhXA34 and PhXA41 after both single an d repeated administrations. PhXA34 and PhXA41 reduced intraocular pres sure (IOP) significantly in a dose-dependent way. The maximum IOP redu ctions were 14.5% to 17.5% with baseline adjustment at 10 to 12 hours after a single administration. No transient early elevation in IOP aft er treatment was observed. Based on the maximum IOP reducing effect of 1 mug of PhXA34 and PhXA41, PhYA41 appeared to be at least 1.5 times more active than PhXA34. Tachyphylaxis of the ocular hypotensive effec t did not develop during repeated administration for 5 days. A mild co njunctival hyperemia occurred in some subjects at high doses; it tende d to diminish with time during the repeated administration of both dru gs. Neither PhXA34 nor PhXA41 caused any change at any time in the aqu eous flare intensity measured with a laser flare-cell meter. There wer e no changes in pupillary diameter after treatment. Each drug was well tolerated and caused no other ocular or systemic side effects.