Tag: Viagra (Page 2)

OCULAR SAFETY OF VIAGRA (SILDENAFIL CITRATE): CLINICAL STUDIES

Cognizant of the preclinical data, substantial efforts were made to investigate the visual effects of sildenafil during clinical development. A number of Phase II and III studies were carried out to determine the safety of sildenafil in relation to the retina and visual function. Much of the data, with complete study descriptions, will appear in […]

BACKGROUND: THE DEVELOPMENT OF VIAGRA

Early in preclinical development, it was found that sildenafil inhibits retinal PDE6 enzymes with an IC50 of 27-58 nM. Although this was substantially less than its effect on the intended target, PDE5 (IC50 3.9 nM), it led to the evaluation of safety of high doses of sildenafil on retinal histopathology in rats and dogs and […]

OCULAR SAFETY OF VIAGRA (SILDENAFIL CITRATE): INTRODUCTION

Viagra (sildenafil citrate) is the first of a new class of orally effective treatments for erectile dysfunction. It potently inhibits cGMP-specific phosphodiesterase type 5 (PDE5) (Fig 1), found in high concentrations in the smooth-muscle cells of corpus cavernosum and in lesser concentrations in blood vessels of the systemic circulation. Because of its ability to act […]

OCULAR SAFETY OF VIAGRA (SILDENAFIL CITRATE): ABSTRACT

To date, sildenafil citrate (Viagra) gives every evidence of being a safe drug for the eye despite a series of expressed concerns. A review of how its ocular safety profile has been identified offers insights into the strengths and weaknesses of present systems and resources for judging the ocular safety of Viagra or, for that […]