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).

The diagnosis of ED in a patient may affect its management in two ways.30 The first relates to the fact that the ED patient, irrespective of whether he has or has not established CVD, is ‘reclassified’ into a higher risk category for future CV events. Management in this case is altered in the sense that more aggressive treatment of risk factors, as well as a close follow-up, is warranted. Implementation of biomarkers in this setting is desirable.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References The use of any NO-donor medications should be avoided for 24 hours after the last dose of sildenafil and even longer if there is a suspected prolonged half-life secondary to such conditions as renal insufficiency.10x10Kloner, RA and Zusman, RM. Cardiovascular effects of sildenafil citrate and recommendations for its use. Am J Cardiol. 1999; 84: 11N–17N
There are two kinds of penis implants. One kind is a rigid but flexible rod implanted in the penis. You bend it up for sex or down for daily living. The other kind is an inflatable implant. The device stores fluid in a reservoir under the skin of your abdomen or scrotum. You press on the reservoir to pump fluid into cylinders in the penis. That creates an erection. A valve drains the fluid out of the penis when you're done.
In many of these cases, a discussion between the physician, the man with erectile dysfunction, and possibly his partner can help to resolve the issues leading to treatment failure. For men who experience severe side effects, can’t take the drugs for other reasons (such as taking medicines such as nitroglycerin), or don’t respond in spite of further education on the correct use of the drugs, there are other treatment options that can help most men remain sexually active.
Intraurethral alprostadil (Muse) provides a less invasive alternative to intrapenile injection. It is a pellet that is inserted 5–10 min before intercourse, and its effects last for 1 h. The response rate is ∼50–60%. It can be used twice daily but is not recommended for use with pregnant partners. Complications of priapism and penile fibrosis are less common than after alprostadil given by penile injection. The cost is ∼$18–24 per treatment.

Having ED means that all, most, or some of the time, the penis fails to become or stay hard enough for sexual intercourse. If, on rare occasions, you cannot get an erection, you do not have ED. You also do not have ED if you have a decrease in sexual desire, have premature ejaculation, or if you fail to ejaculate or reach orgasm. ED means that you can’t get or keep an erection.


Not surprisingly, they found that diabetic patients rated kidney disease and blindness as the two most important complications of their condition. Diabetic men with ED ranked ED as the third most important complication of diabetes, followed on average in order by foot ulcers, high blood pressure, high cholesterol, migraine headaches, sleeping disorders, and mild indigestion. Diabetic men without ED found ED slightly less important, ranking it behind foot ulcers and high blood pressure, although all three were grouped fairly close together (mean ranks were 4.59, 4.23, and 4.52, respectively). Interestingly, in men both with and without ED, subjects were willing to pay more per month to avoid ED than all other conditions except blindness and kidney disease (mean values for diabetic patients with ED were £50.5, £88.0, and £66.1, respectively). In summary, erectile function is important to diabetic men, and when ED is present, it has a significant negative effect on quality of life.
Mechanical therapy is also effective and is especially well-accepted in men with stable partners. Vacuum-assisted erection devices are effective in creating erections in as much as 67% of cases. Vacuum pressure encourages increased arterial inflow, and occlusive tension rings discourage venous outflow from the penile corpus cavernosae. The penis placed inside the cylinder, a pump is used to produce a vacuum that pulls the blood into the penis. After the tension ring is slipped onto the base of the penis, the cylinder is removed. Erection lasts until the rings are removed. The one-time expense of this therapy is $120–300.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (58) | Google ScholarSee all References However, if optimally treated with β-blockers, lipid-lowering agents, and aspirin, these patients have no significantly increased cardiovascular risk associated with sexual activity, although they should receive appropriate risk information.88x88Jackson, G. The use of sildenafil in heart disease [editorial]. Hosp Med. 2000; 61: 526–527
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.
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.
Crossref | PubMed | Scopus (335) | Google ScholarSee all References Additionally, the presence of nephropathy has been correlated with onset of ED, as has the length of time the patient has had diabetes; most of these patients experience ED within 10 years of being diagnosed as having insulin-dependent or non–insulin-dependent diabetes mellitus.4x4Feldman, HA, Goldstein, I, Hatzichristou, DG, Krane, RJ, and McKinlay, JB. Impotence and its medical and psychosocial correlates: results of the Massachusetts Male Aging Study. J Urol. 1994; 151: 54–61

Core tip: The prevalence of erectile dysfunction is approximately 2-fold higher in hypertensive patients compared to normotensive individuals. However, erectile dysfunction remains under-reported, under-recognized, and under-treated in hypertensive patients. Lifestyle modification should be the mainstay of treating erectile dysfunction in patients with untreated hypertension. Switching antihypertensive therapy should be considered in treated hypertensive patients, unless administered drugs are absolutely indicated for the individual patient. Otherwise, phosphodiesterase-5 inhibitors should be used, since they are both effective and safe in hypertensive patients. Finally, erectile dysfunction offers the opportunity to recognize asymptomatic cardiovascular disease with obvious benefits for cardiovascular event prevention.

Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References Since then, several other oral PDE-5 inhibitors have been developed, including vardenafil and tadalafil, which generated considerable interest in both the scientific and lay communities. There was also much concern about their safety, especially in men with cardiovascular disease. Compared with the 2 newer PDE-5 inhibitors vardenafil and tadalafil, sildenafil has been available for a much longer time; therefore, the vast majority of published cardiovascular safety studies have been performed on this medication. Recommended starting and maximum doses of oral PDE-5 inhibitors are shown in Table 1.
Men with diabetes tend to develop erectile dysfunction 10 to 15 years earlier than men without diabetes. As men with diabetes age, erectile dysfunction becomes even more common. Above the age of 50, the likelihood of having difficulty with an erection occurs in approximately 50% to 60% of men with diabetes. Above age 70, there is about a 95% likelihood of having some difficulty with erectile dysfunction.
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