Impact of introduction of sildenafil on other treatment modalities for erectile dysfunction: a study of nationwide and local hospital sales

We assess the impact of introduction of sildenafil on alprostadil injection and penile implant surgery for the treatment of erectile dysfunction (ED) at our institution and in Taiwan. The data of national sales of sildenafil, alprostadil injection and penile implant were provided by industry companies. In the meanwhile, we analyzed the users of the above-mentioned three treatments at our institution. The national sales of sildenafil grew 136% from 0.8 million tablets in 1999 to 1.6 million tablets in 2002, while those of alprostadil injection dropped 33% after the marketing of sildenafil and of penile implant dropped 40% after the marketing of alprostadil injection and sildenafil. The market share of drugstores for sildenafil rose from 41% in 1999 to 72% in 2002. The trend of sales of sildenafil at our institution was similar to that of national sales from hospitals. Mean age of the sildenafil new users was becoming younger in the past 4 y ( P<0.001). Of the new users of alprostadil injection and the recipients of penile implant, the commonest age group shifted from the range of 60 - 69 y before the launch of sildenafil to that of over 70 y after ( P<0.05). In conclusion, the introduction of sildenafil has prompted more men as well as younger men with ED to seek treatment. Part of the roles of alprostadil injection and penile implants in this field are substituted by sildenafil and the commonest age group of their users becomes older than before.