Abstract | Full Text | Full Text PDF | PubMed | Scopus (53) | Google ScholarSee all References Early work in this field, performed by Masters and Johnson in 1966, involved evaluation of young patients in a laboratory setting and found that heart rates and systolic blood pressure levels during sexual activity approached levels seen during maximal exercise.84x84Stein, RA. Cardiovascular response to sexual activity. Am J Cardiol. 2000; 86: 27F–29F
Abstract | Full Text | Full Text PDF | PubMed | Scopus (24) | Google ScholarSee all References Erectile function relies on the arterial blood supply from the internal pudendal arteries, which are branches of the hypogastric arterial system (Figure 1). Substantial increases in internal pudendal arterial flow result in pressures within the penis that are comparable to systemic arterial levels.12x12Rampin, O and Giuliano, F. Central control of the cardiovascular and erection systems: possible mechanisms and interactions. Am J Cardiol. 2000; 86: 19F–22F
PubMed | Google ScholarSee all References As with sildenafil, use of nitrate or NO-donor medications is contraindicated while taking tadalafil because of the potential for marked hypotensive interactions.74x74Gresser, U and Gleiter, CH. Erectile dysfunction: comparison of efficacy and side effects of the PDE-5 inhibitors sildenafil, vardenafil and tadalafil—review of the literature. Eur J Med Res. 2002; 7: 435–446
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).
Since 1998, when sildenafil (brand name Viagra) first came on the market, oral therapy has been successfully used to treat erectile dysfunction in many men with diabetes. (Sildenafil was followed in 2003 by the drugs tadalafil [Cialis], vardenafil [Levitra] and avanafil [Stendra], which work in much the same way.) Some 50% of men with Type 1 diabetes who try the drugs report improved erections, and some 60% men with Type 2 diabetes do, too. However, that leaves a large percentage of men with diabetes and erectile dysfunction who do not respond to therapy with one of these pills. This article takes a look at what can be done to treat those men who do not respond to oral therapy.