Emerging oral drugs for erectile dysfunction

Abstract

Erectile dysfunction (ED) is a common medical condition that affects the sexual life of millions of men worldwide. Many drugs are now available for the treatment of ED, with oral pharmacotherapy representing the first-line option for most patients. Sildenafil citrate, an inhibitor of the enzyme phosphodiesterase type 5 (PDE5), is the most widely prescribed oral agent and has a very satisfactory efficacy-safety profile in all patient categories. Tadalafil (Cialis; Eli Lilly & Co., ICOS) and vardenafil (Levitra; Bayer Pharmaceuticals, GlaxoSmithKline) are new PDE5 inhibitors that have recently been approved worldwide. Both have been associated with significant positive efficacy-safety profiles. Apomorphine sublingual is a dopamine D1 and D2 receptor agonist, which has been approved for marketing in Europe. It is best selected for treating patients with mild-to-moderate ED, but it is seldom used in clinical practice due to its limited efficacy and side effects, particularly nausea. Patients who do not respond to oral pharmacotherapy or who are unable to use it are appropriate candidates for intracavernosal and intraurethral therapy. The efficacy of second-line treatment is high, but the attrition rate remains significant. For the purpose of this review, clinical and pharmacological analysis focuses on the recent advances in the field of oral therapy, including PDE5 inhibitors and sublingual apomorphine.