Viagra : Is It a Wonder Drug ?

Abstract

Male erectile dysfunction is common and frustrating after the age of forty years. Erectile dysfunction is a cause of misery, relationship difficulties, and significantly reduced quality of life. Sildenafil citrate (Viagra) has shown promising results in recently published clinical trials. Slldenafil is a potent and competitive inhibitor of cGMp specific phosphodiesterase-S, predominant isoenzyme in the human corpus cavernosum, It is effective in erectile dysfunction of diverse origin, however it requires a patent vascular system to be effective. It is not effective in patients with endocrinal impotence, loss of libido, premature ejaculation or infertility. Its main adverse effects are headache, flushing, dyspepsia, diarrhoea, nasal congestion, indigestion, visua1 disturbances, dizziness and rash. Ventricular tachycardia and acute myocardial infraction have been reported in patients of ischaemic heart disease after consumption of siidenafil. Six deaths have been reported in patients taking nitrates. In India it is likely to be prescribed by a primary care physician without complete evaluation of patient on complaint of impotence. Hence the ethical question of who should prescribe this drug should be addressed by medical fraternity and proper guidelines formulated to avoid misuse of sildenafil. Phosphodiesterase is distributed in nerve, central nervous system, and systemic vasculature, hence long-term effects of drug on these tissues has to be ascertained. It should be made mandatory to report all adverse drug reactions to ADR monitoring centres. It is a wonder for those who require it, but has potentially dangerous adverse effects and drug interactions and hence is and not a wonder pill for all kinds of impotence. MJAFI 2001; 57 : 44·46

New Approaches in Oncology for Repositioning Drugs: The Case of PDE5 Inhibitor Sildenafil

“…In 1985, Pfizer's project leader, Dr. Simon Campbell, carried out preclinical trials for the compound UK-92-480, which was capable to induce coronary artery dilatation in patients (15,16). During these trials, men reported an erectogenic effect with the UK-92-480.…”