Erectile Dysfunction (ED) is the most common male sexual dysfunction presented for treatment, and the most thoroughly studied sexual dysfunction in men. In the late 20th century, important discoveries were made regarding both the physiologic processes of penile erection and the pathophysiology of ED. These discoveries led to the commercial introduction of the phosphodiesterase type 5 inhibitors (PDE5I), a class of medications which now accounts for the largest segment of the ED market. While these drugs are highly efficacious for many men, a relatively large subset of ED patients who do not respond to PDE5I has been identified. Recognition of this subset of the ED population and the ageing of the population has driven researchers to investigate novel treatment targets for ED. Increased research efforts have resulted in the development of several orally available compounds that combine high efficacy with low rates of adverse events. In this review we report on various compounds that regulate penile erection both centrally (Clavulanic acid, Dopamine and Melanocortin receptor agonists) and peripherally (novel PDE5I, soluble and particulate Guanylil Cyclase activators, Rho-kinase inhibitors and Maxi-K channel openers), and discuss the preclinical and clinical evidence supporting the development of these emerging drugs for ED.

Introduction High-flow priapism (HFP) may occur secondary to perineal trauma, congenital arterial malformations, and iatrogenic insults. In cases that do not resolve spontaneously, standard management is by selective embolization, resulting in resolution rates as high as 78%; however, erectile dysfunction (ED) is a frequent complication, occurring in up to 39% of cases. Aim We report our use of androgen blockade (AB) to suppress nocturnal erections as an alternative treatment for HFP. Methods A retrospective review of all patients treated at our institution for HFP was undertaken. Included in this study were any patients treated with single- or combination-agent AB for HFP. Operative reports and medical records were examined to determine patient characteristics and outcomes. Treatment efficacy, side effects, and residual ED were assessed using a questionnaire. Main Outcome Measures The primary clinical outcomes assessed were resolution of HFP, tolerability, and side effects of treatment. Results Seven patients with HFP were treated with AB. Priapism was a result of trauma in three patients and a persistent high-flow state after shunt procedures in four. Mean follow-up was 2 years (range 4 to 64 months). Therapy consisted primarily of 7.5 mg intramuscular monthly leuprolide injections, although bicalutamide and ketoconazole were also utilized as adjunct treatments. Therapy duration ranged from 2 months to 6 months and was discontinued after symptom resolution. One patient discontinued daily ketoconazole after 1 week because of severe hot flashes. The remaining six patients reported complete resolution of HFP. The primary complaints during therapy were decreased libido and fatigue. All patients reported some degree of ED during therapy. There was no reported residual ED or other hypogonadal symptoms on withdrawal of therapy. Conclusion AB is a successful option for treating HFP with acceptable side effects and return to baseline potency on treatment withdrawal.

Erectile dysfunction (ED) is a prevalent and important disease that has been associated with various comorbidities. The evaluation of patients with ED should include a general health assessment followed by a discussion of reversible factors and lifestyle changes that might help preserve erectile capacity. Numerous effective treatment options are currently available. A frank discussion about use and side effects of these therapies is required to optimize success. Although oral pharmacologic treatments can be initiated and monitored by the primary care physician, patients who do not experience response to these treatments may be best served by referral to a sexual medicine specialist for further assessment and consideration of other treatment options. This article discusses the physiology and pathophysiology of erectile function in men, how the primary care physician may address the clinical problem of ED in practice, and when specialty referral is indicated.