When it comes to combating heart disease, most information sources promote drugs and surgery as the only viable options, with lip service to dietary advice that simply does not work. As a result, the demand for high-tech, expensive, but largely ineffective medical care is soaring, causing medical costs and insurance rates to skyrocket. This chase for "cures" is both financially devastating and futile. Morbidity and premature mortality from heart disease continue to rise, with no sign of abating.
Following the breakthrough in ED treatment using PDE5-inhibitors, Western medicine has now moved on to a new frontier of regenerative medicine, with stem cell and gene therapy leading the way (25). There is a practical need for novel therapy as a significant portion of diabetic or post-prostatectomy ED patients do not respond to oral pharmacotherapy. To date, stem cells derived from different sites including adipose tissue-derived stem cells, bone marrow mesenchymal stem cells and muscle-derived stem cells have been investigated using animal models for ED, to study their effects on neural, vascular, endothelial or smooth muscle regeneration (25,26).
Most studies into the effect of beta-blockers on ED point to negative effects of first- and second-generation beta-blockers, while beta-blockers with vasodilating effects can improve erectile function. Alpha-blockers, calcium channel blockers, and angiotensin-converting enzyme inhibitors seem to have a neutral effect on erectile function. Multiple previous studies have demonstrated a beneficial effect of angiotensin receptor blockers on erectile function and they should probably be the favoured antihypertensive agents in patients with ED.29
Hypertension can affect endothelial function in many ways. It can reduce endothelium-dependent vasodilatation by increasing the vasoconstrictor tone as a result of increased peripheral sympathetic activity.41–43 Another mechanism is hypertension-induced increase in cyclooxygenase activity that leads to an increase in reactive oxygen species; these in turn damage endothelial cells and disrupt their function.44–46 In some cases, endothelial NO synthase (eNOS) gene variations may relate to hypertension-associated endothelial dysfunction.6
Current American College of Cardiology/American Heart Association guidelines quote an absolute contraindication to sildenafil use in the setting of chronic nitrate treatment or the use of short-acting nitrate medications.10x10Kloner, RA and Zusman, RM. Cardiovascular effects of sildenafil citrate and recommendations for its use. Am J Cardiol. 1999; 84: 11N–17N
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.