EFFECTS OF PHOSPHONYLMETHOXYALKYL-PURINE AND PHOSPHONYLMETHOXYALKYL-PYRIMIDINE DERIVATIVES ON TK+ AND TK- HSV-1 KERATITIS IN RABBITS

The phosphonylmethoxyalkyl derivatives HPMPA [(S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine], HPMPC [(S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine] and PMEA [9-(2-phosphonylmethoxyethyl)adenine] were evaluated as 0.2% eyedrops for their efficacy in the treatment of experimental herpes simplex virus type 1 (HSV-1) keratitis in the rabbit model. BVDU 0.2% eyedrops were used as the reference treatment. HPMPA, HPMPC, PMEA and BVDU eyedrops showed a rapid and highly significant healing effect (P < 0.005) on keratitis caused by TK+ HSV-1 (McIntyre strain) when compared with placebo eyedrops, whereas BVDU treatment did not affect the course of TK- HSV-1 (VMW-1837) keratitis. HPMPA and HPMPC treatment again caused a highly significant healing (P < 0.005, compared with placebo eyedrops). Although PMEA eyedrops were less effective than HPMPA or HPMPC eyedrops, the effect of PMEA eyedrops was significantly (P < 0.05) different from the effect of either BVDU or placebo eyedrops.