Co-authors Stacy Mandras, M.D., Patricia Uber, Pharm. D., and Mandeep Mehra, M.D., conducted systematic independent literature searches using the MEDLINE database and examined a broad range of medical research that focused on chronic heart failure, sexual activity and sexual dysfunction. This literature included data from patient surveys and clinical trials.
A similar situation develops in the fragile penile circulation. Any disturbance in nitric oxide production lowers the capacity to dilate penile arteries, impairing penile engorgement for erection. Release of nitric oxide is readily sabotaged by many conditions, including elevated levels of cholesterol, high blood pressure, increased triglycerides, smoking, metabolic syndrome and diabetes, and excessive consumption of dietary saturated fat.9 If an artery’s inner wall can’t produce nitric oxide, an abnormal constriction of the arteries to the penis follows, effectively choking off blood flow.
As a primary care doctor, my most important job is to tailor treatment for my patients while still making decisions based on the medical literature. So when patients tell me their treatment is causing undesired side effects—like ED—I work with them to create a plan to treat the condition while also finding a way to relieve those side effects. Fortunately, there are ways to deal with medically induced ED.
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).
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.