A disruption anywhere along the complex chain of events will impair the capacity to have an erection. Any man who has experienced the frustration of male impotence knows that the consequences extend beyond physical dissatisfaction to anxiety, tension, and embarrassment. A common reason for failure of the erectile apparatus is disruption of the path leading to nitric oxide production and blood flow control.
Penile arterial supply (top) and venous drainage (middle), longitudinal views. Bottom, Transverse and longitudinal views of venous return. From Lue TF. Physiology of penile erection and pathophysiology of erectile dysfunction and priapism. In: Walsh PC, Retik AB, Vaughan ED Jr, Wein AJ, eds. Campbell's Urology. Vol 2. 7th ed. Philadelphia, Pa: WB Saunders Co; 1998:1157-1179. With permission from Elsevier.
Since their introduction in the therapeutic field, more than a decade ago, PDE-5 inhibitors have revolutionized the treatment of sexual dysfunction. By blocking the activity of PDE-5 isoenzyme, localized throughout the smooth muscle cells of the vasculature (genital vessels included), PDE-5 inhibitors increase the levels of cyclic guanosine monophosphate thus exerting vasodilating properties and facilitating penile erection[40-42]. Due to these properties, sildenafil was the first drug of its class to receive wide acceptance. Its short half-life, food interactions and the associated visual disturbances however, paved the way for the development of newer PDE-5 inhibitors. As such vardenafil with its more rapid onset of action, and tadalafil with its longer half-life and the lack of food interactions or side effects, have offered significant alternatives to sildenafil[43-50].
Based on this testing, EDDM patients were treated with behavioral therapy, intracavernosal (papaverine, PGE-1, or Trimix) or intraurethral PGE-1, a vacuum constriction device (VCD), or implantation of a penile prosthesis. Novel surgical procedures, ligation of incompetent cavernosal veins or penile revascularization, were seldom efficacious with EDDM and were soon abandoned. Although these nonsurgical therapies were efficacious, they were not widely requested because of their invasive or mechanical nature.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (164) | Google ScholarSee all References Several double-blind, placebo-controlled studies have shown vardenafil to be more effective than placebo in the treatment of ED secondary to a wide range of other etiologies as well.71x71Hellstrom, WJ, Gittelman, M, Karlin, G..., and Vardenafil Study Group. Sustained efficacy and tolerability of vardenafil, a highly potent selective phosphodiesterase type 5 inhibitor, in men with erectile dysfunction: results of a randomized, double-blind, 26-week placebo-controlled pivotal trial. Urology. 2003; 61: 8–14
The use of shock wave therapy has revolutionized the treatment of many aspects of medicine. High intensity extracorporeal shockwave therapy has been used for the treatment of nephro-urolithiasis while medium intensity shockwave therapy is used by orthopaedic surgeons to treat joint pain as well as tendinitis. Low intensity shockwaves therapy was first noted to improve ischaemia-induced myocardial dysfunction in animal studies when low intensity shockwaves were applied to porcine myocardium (13). Shockwaves induces a localized stress on cell membranes in the same way that shear stress affects endothelial cell membranes (14) and this triggers the release of angiogenic factors, such as increased NO production through increased activity of endothelial NO synthase (eNOS) and neuronal NO synthase (nNOS), platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) (15). These shockwaves also cause membrane hyperpolarization (16), activation of the Ras signaling pathway, non-enzymatic synthesis of NO and induction of stress fibers and intercellular gaps (17).
A nutrient-dense, plant-rich (Nutritarian) diet is a huge defense. When men eat for optimal health, they protect their heart, prostate, brain, and, in effect, the entire body. A nutrient-dense, plant-rich (Nutritarian) diet floods the body with protective nutrients, and supports a healthy weight. It not only normalizes risk factors for heart disease and diabetes, but also offers a substantial level of protection against common cancers.
The vacuum constriction device consists of a vacuum cylinder, various sizes of tension rings, and a vacuum pump, either hand-operated or electric. The penis is placed in a cylinder to which a tension ring is attached. Air is evacuated from the cylinder by means of the pump, creating a vacuum, which produces the erection. The cylinder is removed, leaving the tension ring at the base of the penis to maintain the erection.
Table 3Metabolic Equivalent (MET) Values for Various Physical Activities56x56Wallis, RM, Corbin, JD, Francis, SH, and Ellis, P. Tissue distribution of phosphodiesterase families and the effects of sildenafil on tissue cyclic nucleotides, platelet function, and the contractile responses of trabeculae carneae and aortic rings in vitro. Am J Cardiol. 1999; 83: 3C–12C
Getting frequent exercise and maintaining a healthy weight are, of course, also important. Plus, avoiding or minimizing risky dietary factors such as salt, alcohol, caffeine, and too much animal products is crucial. Animal protein elevates insulin-like growth factor 1 (IGF-1) in the blood, a growth-promoting hormone that is associated with increased risk of several cancers and cardiovascular disease.19, 20
The discovery in 1992 of the second messenger of cavernosal smooth muscle relaxation was the critical step that led to the era of nonhormonal oral drug therapy for ED. In 1998, the multicenter trial of sildenafil in the treatment of ED was published in the New England Journal of Medicine, and the era of the phosphodiesterase type 5 (PDE-5) inhibitor began.1 For 5 years, sildenafil was the primary therapy for men with EDDM. Recently, 2 new PDE-5 inhibitors, vardenafil and tadalafil, were introduced.
In the vessels that supply the heart, healthy arteries enlarge in diameter up to 50% during exercise when sufficient nitric oxide is present. Because of its brief half-life, a continual supply of nitric oxide is required for optimal effect. If the supply of nitric oxide is inadequate, endothelial dysfunction—a core factor in heart disease—is made worse. Endothelial dysfunction can trigger the growth of coronary plaque.8
Abstract | Full Text | Full Text PDF | PubMed | Scopus (25) | Google ScholarSee all References Patients with prior cardiac events should be encouraged to enroll in cardiac rehabilitation programs before restarting sexual activity.80x80Muller, JE. Triggering of cardiac events by sexual activity: findings from a case-crossover analysis. Am J Cardiol. 2000; 86: 14F–18F
According to the Cleveland Clinic, “because erectile dysfunction is caused by a complex set of psychosocial, neurologic, and vascular factors, a specific cause in a patient may remain ambiguous.” The root causes are often related to a blockage or dysfunction of blood vessels. For example, ED can be due to conditions like atherosclerosis or diabetes, hormonal imbalances or problems related to mental health. It’s been found that common causes typically include one or more of the following factors: (2)
After analyzing 28 previous studies on the link between ED and heart disease, the researchers found a connection between erectile dysfunction and poor endothelial function. “Blood vessels are unable to fully dilate and allow blood to flow through,” explains Medicalnewstoday.com. “Endothelial dysfunction is an early sign of atherosclerosis, a condition in which plaque builds up in the arteries, raising the risk of heart attack and stroke.” The researchers also determined that there was a thickening of one of the inner two layers of the carotid artery—another heart-disease indicator.
The use of penile support device such as penile cast worn externally during intercourse has been tried to provide length and rigidity to the penile shaft (24). Each device can be customised to the patient’s penile size and provided an option for patients who are seeking non-pharmaceutical/non-invasive treatment, or have end-organ failure who may not be candidates for, or unable to afford, penile prosthesis implant.
There are a number of reasons a man may not achieve the desired result from an oral erectile dysfunction drug. In some cases, a man may experience drug side effects severe enough to outweigh any potential benefit of taking the drug. Possible side effects of these drugs include headache, facial flushing, nasal congestion, and transient abnormal vision. (In October 2007, the FDA added a warning about sudden hearing loss to the package labels of oral erectile dysfunction drugs. While it’s not absolutely clear that the drugs can cause sudden hearing loss, a number of cases have been reported in men within hours or days of taking one of the drugs.)