The 1980s saw a progressive shift away from psychological treatments of sexual dysfunction to an emphasis on surgical and medical solutions for improving sexual health. Simultaneously, there was a progressive shift within the medical community and public at large, towards viewing the etiology of sexual dysfunction as organic, rather than the psychogenic understanding emphasized by sex therapists. Use of improved sophisticated diagnostic procedures, such as duplex sonography and cavernosograms (although not necessarily improving treatment) added credibility and imprimatur to the importance of organic pathogenesis. This was particularly true in the area of erectile dysfunction, where urologists established dominance, with the successful marketing and use of various intracavernosal and intraurethral systems. Although highly touted by urologists, the treatment efficacy of these products was offset by their intrusiveness into the patients bodies and reduction in spontaneity, their patterns of use required.
Initially, there were few oral treatments for erectile dysfunction, being used by urologists, such as yohimbine based products, trazodone, and bupropion. They had only modest proerectile capability. Pharmaceutical companies were inspired to pursue oral treatments with the promise of less intrusiveness and even greater profits. The first visible evidence of fulfilling that promise was the sildenafil launch. Subsequent to Pfizers success, multiple companies simultaneously pursued clinical trials of easy-to-use treatments for male sexual dysfunction. Among others, these included additional PDE-5 type compounds and other oral treatments, such as ixense (TAP Holdings, Deerfield, IL, USA), and topically applied compounds (MacroChem, Lexington, MA, USA). Additionally, PT-141 (Palatin Technology, Cranbury, NJ, USA) is a nasally administered peptide that is under development, which is presumed to work through a central nervous system mechanism.
Currently, there are three highly efficacious PDE-5, FDA-approved treatments for erectile dysfunction: sildenafil, vardenafil, and tadalafil. Reviews of long-term extension studies and published accounts of use in clinical practice show that sildenafils effectiveness was maintained with long-term treatment. “Significantly improved erectile function was demonstrated for sildenafil compared with placebo for all efficacy parameters analyzed (P , 0.02 to 0.0001), regardless of patient age, race, body mass index, erectile dysfunction etiology, erectile dysfunction severity, erectile dysfunction duration, or the presence of various co morbidities. Long-term effectiveness was assessed in three open-label extension studies.” Vardenafil (launched in 2003) “is a potent, selective PDE-5 inhibitor, which improved erectile function in a broad population of men with erectile dysfunction and in characteristically challenging-to-treat groups such as diabetic and post prostatectomy patients.” Tadalafil also launched in 2003, when taken, “as needed before sexual activity and without restrictions on food or alcohol intake, significantly improved erectile function. It allowed a substantial proportion of patients to achieve a normal IIEF erectile function domain score, exhibited a broad window of therapeutic responsiveness and was well tolerated in a representative population of patients with broadspectrum erectile dysfunction.”