Vasoactive intestinal polypeptide/phentolamine for intracavernosal injection in erectile dysfunction

Erectile dysfunction (ED) is becoming an increasingly common problem and although oral therapies offer first-line treatment for many men, they are contraindicated or ineffective in substantial groups of patients. Intracavernosal injection (ICI) therapy is the most effective nonsurgical treatment for ED and offers an effective alternative to oral therapy. Sufficient arterial blood supply and a functional veno-occlusive mechanism are prerequisites in the attainment and maintenance of a functional erection. Invicorp (Plethora Solutions, London, UK) is a combination of vasoactive intestinal polypeptide (VIP) 25 microg and phentolamine mesylate 1 or 2 mg for ICI in the management of moderate to severe ED. The two active components have complementary modes of action; VIP has a potent effect on the veno-occlusive mechanism, but little effect on arterial inflow, whereas phentolamine increases arterial blood flow with no effect on the veno-occlusive mechanism. Clinical studies showed that Invicorp is effective in >or=80% of men with ED, including those who have failed to respond to other therapies and, unlike existing intracavernosal therapies, is associated with a very low incidence of penile pain and virtually negligible risk of priapism. We estimate that there are >5.9 million men in the USA alone for whom oral ED drugs are not a viable treatment option, and for whom Invicorp might offer a safe and effective alternative.