Phosphodiesterase-5 inhibitors

Erectile dysfunction (ED) can occur at any age, but its prevalence increases with age. Whilst the proportion of men affected aged between 40 and 49 is around 20%, this figure rises to around 50% for a 70-year-old man. Successful treatment of erectile dysfunction would not only provide sexual satisfaction for those affected, but also enhance their overall well-being and zest for life. In many cases, the first step in treating ED is pharmacotherapy. Originally, this treatment was carried out solely using locally acting agents such as papaverine, phentolamine and prostaglandin; it was not until between 1980 and the first half of the 1990s that orally administered agents such as yohimbine, terazosin and apomorphine came onto the market. By the late 1990s, understanding of the physiology and molecular mechanisms of ED had improved significantly, which spurred the development of new, orally administered medicines for the treatment of ED. The first of these medicines to reach the market was sildenafil, followed later by vardenafil and tadalafil.