Update on oral treatments for male erectile dysfunction

Abstract

Impairment of erectile function compromises quality of life in millions of men and their partners, many of whom prefer to suffer in silence. It is important to maintain an elevated index of clinical suspicion in patients with erectile dysfunction (ED) risk factors (e.g. hypertension, diabetes, coronary heart disease). There remains a high rate of voluntary discontinuation of therapy associated with most treatment modalities. Since the introduction of sildenafil, a greater awareness and openness regarding the epidemiology and treatment of male erectile dysfunction has emerged. The development of newer and potentially more efficacious phosphodiesterase type 5 (PDE5) inhibitors will serve to treat an even greater number of patients, allowing once daily and more convenient dosing. An increased understanding of the physiological principles of penile erection has allowed the development of novel oral pharmacological therapies. The new agents offer a potential benefit in a broader range of patients and clinical situations. They may provide a more acceptable alternative than other more invasive options (intracavernosal/urethral injection, implant surgery). The dopamine agonist apomorphine acts on the central control of penile erection to allow a sublingual preparation to produce a prompt response. It is not contraindicated in patients on nitrate medication for coronary artery disease, or in patients with depression or on antidepressants. As with any other treatment, the clinician's responsibility in the care of ED patients does not end with the writing of a prescription. Adequate education and follow-up are needed to optimize the efficacy and safety of oral ED therapy. Furthermore, patients and their partners need to be advised that the agents are not effective in the absence of sexual stimulation. Communicating with both the patient and his partner in a discreet, non-judgmental manner that fosters the physician-patient alliance can facilitate the recognition and treatment of ED.

Phosphodiesterase type 5 inhibitors’ extended duration of response as a variable in the treatment of erectile dysfunction

“…Patient follow-up visits provide an opportunity for the clinician to monitor side effects, determine whether medication is being used correctly, provide reinstruction if necessary, ask about the couple's satisfaction with treatment and assess the couple's overall health and relationship status. 13,[42][43][44] In general, the concept of relapse prevention has not been incorporated into sexual medicine, yet sexual dysfunction is recognized as a progressive disease in terms of underlying organic pathology, which may play a role in altering the threshold for response and the potential re-emergence of ED. 15,24 To summarize, the main areas of therapeutic focus when a couple confers with their clinician and attempts to re-establish their sexual relationship with ED treatment are: 15 Identify what the couple's established sexual patterns and habits were before the onset of ED.…”

The recent phosphodiesterase type 5 inhibitors

“…In all trials, those men receiving a PDE5 inhibitor reported erections sufficient for sexual intercourse more often than did those who received placebo [6]. However, the action of PDE5 inhibitors requires an unimpaired neuronal input into the corpus cavernosum, as well as intact cavernous endothelial structures.…”

Avanafil for erectile dysfunction in elderly and younger adults: differential pharmacology and clinical utility

“…The first line of medical therapy for ED is phosphodiesterase (PDE) 5 inhibitors 1,6,7. These drugs augment the natural physiologic process of tumescence 6,8.…”

“…These drugs augment the natural physiologic process of tumescence 6,8. During penile erection, nitric oxide stimulates cyclic guanosine monophosphate (cGMP) production in vascular smooth muscle cells of the corpus cavernosum 6,9.…”