Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References Sildenafil is absorbed rapidly, and peak plasma levels of 127 to 560 ng/mL are seen in a fasting state approximately 1 hour (range, 0.5-2 hours) after ingestion.3x3Zusman, RM, Morales, A, Glasser, DB, and Osterloh, IH. Overall cardiovascular profile of sildenafil citrate. Am J Cardiol. 1999; 83: 35C–44C
Now that we better appreciate the complex sequence of events necessary for erections to occur, it’s no surprise that testosterone alone yields less than perfect results. Erectile dysfunction represents more than just low testosterone, which is just one facet of the spectrum of dysfunctional phenomena that cause sexual dysfunction. Nonetheless, when testosterone is combined with popular drugs like Viagra®, success is enhanced to an even greater degree—orgasmic function improves, along with erectile capacity and libido.20 Testosterone also activates penile nitric oxide; ultrasound studies have demonstrated a 27% increase in arterial blood flow into the penis with testosterone supplementation.23
The study, which retrospectively tracked more than 43,000 men for an average of 3.3 years, found that men prescribed phosphodiesterase-5 (PDE5) inhibitors—the type of erectile dysfunction drug sold under the names Viagra, Levitra, Cialis and others—after their first heart attack were 38 percent less likely to die from any cause. No survival benefit was seen among men taking alprostadil, another type of erectile dysfunction drug that works through a different mechanism.
Crossref | PubMed | Google ScholarSee all References After controlling for age, trauma, hypertension, and diabetes mellitus, a study of 97 young patients with ED who underwent selective pudendal angiography showed a significant relationship between lifetime cigarette smoking and the degree of internal pudendal and common penile arterial atherosclerosis.28x28Rosen, MP, Greenfield, AJ, Walker, TG et al. Cigarette smoking: an independent risk factor for atherosclerosis in the hypogastric-cavernous arterial bed of men with arteriogenic impotence. J Urol. 1991; 145: 759–763
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Abstract | Full Text PDF | PubMed | Scopus (19) | Google ScholarSee all References However, there has been disagreement regarding the effects of diuretics on erectile function; many studies found that only rarely have these medications been implicated convincingly as the cause of a patient's ED.36x36Wein, AJ and Van Arsdalen, KN. Drug-induced male sexual dysfunction. Urol Clin North Am. 1988; 15: 23–31
Although DM patients often correctly assume that their ED is of organic origin, a psychogenic component should be considered, especially in the younger patient. If this is the case, the patient may benefit from psychosocial therapy that includes anxiety reduction and desensitization, cognitivebehavioral intervention, sexual stimulation techniques, and interpersonal assertiveness with couples communication training.6 Not all healthcare providers offer these options. Freudian-based psychotherapy for EDDM has not been proved to be efficacious.
Beta-blockers: A popular blood pressure medication that affects part of the nervous system in an attempt to slow and regulate heartbeats, helping reduce blood pressure. Unfortunately, this same part of the nervous system is also responsible for causing erections, and when beta blockers are used, it indirectly reduces the amount of blood flow to the penis.
When these drugs don't work, there are other options. Medications that dilate blood vessels, such as alprostadil, can be injected or deposited in the penis; they work in more than 80 percent of men with diabetes. Beyond that, penile implants can be an effective surgical solution. Implants are either malleable rods, which can be manually adjusted to the desired position, or inflatable cylinders that fill with fluid when a pump under the skin of the scrotum is pressed.
Physical and emotional stress — whether over-exercising, under-sleeping or just dealing with everyday stressors like work and a busy schedule — causes an increase in “stress hormones,” including cortisol and adrenaline. Stress can lower desire for sex. This is because stress can contribute to fatigue or preoccupation with other tasks. It can also significantly affect blood flow by increasing inflammation.
The blood supply to your penis starts in your heart and flows through arteries in the belly to even smaller arteries that branch off to carry blood into the penis. With sexual stimulation, these blood vessels need to rapidly increase blood flow. If these blood vessels are blocked (atherosclerosis) by coronary artery disease, you may not be able to achieve or maintain an erection.11
Currently, the preferred treatment for erectile dysfunction includes sildenafil (Viagra), vardenafil (Levitra) and tadalafil (Cialis). However, numerous experts have raised concerns about the use of these drugs in patients with chronic heart failure who also take nitrates (or other medications that relax and widen blood vessels). This drug combination has been shown to be dangerous, because it can increase the risk for a life-threatening drop in blood pressure.
There are other treatment options for erectile dysfunction (ED). Alprostadil is a medication that improves blood flow to the penis and improves erections. It can be given either by injection (Caverject and other brands) at the base of the penis or by putting an alprostadil gel (brand name MUSE) directly into the urethra, using a thin tube and a little lubricant so it slides in easily. The medicine is absorbed from the lining of the urethra into the surrounding tissues. The shot is less appealing to most people, of course, but more effective.
PubMed | Google ScholarSee all References More recently, researchers have recognized that climbing stairs does not correlate closely with sexual activity in terms of autonomic, psychological, and emotional patterns of stress on the body.1x1Muller, JE. Sexual activity as a trigger for cardiovascular events: what is the risk?. Am J Cardiol. 1999; 84: 2N–5N
Diabetes is known to sabotage two body parts that provide essential components of an erection: nerves and blood vessels. Studies suggest that diabetic nerve damage (neuropathy) is the most important risk factor for ED in people with diabetes. If pelvic nerves that trigger penis muscles to relax are impaired, there may be a break in the chain between brain and penis, disrupting erection. Some researchers suspect that an inadequate supply of oxygen to the nerves causes this damage.
Erectile dysfunction carries an independent risk for cardiovascular events. A considerable number of studies have examined the ability of ED to predict the risk of future fatal and non-fatal cardiovascular events (myocardial infarction, stroke, revascularization) and total mortality in the general population and in high CV risk patients, in diabetics and in heart failure patients.5,19–22 In a meta-analysis of 14 prospective cohort studies involving 92 757 men followed for a mean period of 6.1 years (Figure 4), ED increased significantly and independently of traditional risk factors the risk of CV events, CV mortality, myocardial infarction, cerebrovascular events, and all-cause mortality by 44, 19, 62, 39, and 25% respectively.5 This predictive ability also extends in men with known CVD: ED increased the risk of all-cause mortality by 90%.5 Of importance, the predictive ability of ED is higher in younger ED patients5 despite the fact that probability of ED increases with age, most likely identifying a group of patients with early and aggressive vascular disease.23 Clinical implementation of ED as a biomarker relies on whether its addition on classical risk scores such as the Systematic COronary Risk Evaluation (SCORE) or the Framingham correctly reclassifies a meaningful percentage of patients into a higher or lower risk category. To this end, data are limited. Yet, in a population-based study of men 40–70 years of age, the addition of the ED status to the Framingham risk score resulted in a reclassification of 6.4% of low-risk patients to intermediate risk.19
Penile prosthesis is a viable option for men who cannot use sildenafil and who find the injections or vacuum erection therapy distasteful. A non-adjustable semi-rigid prosthesis is easy to insert and has no postoperative mechanical problems. The inflatable prosthesis has a pump that is put in the testicular sac for on-demand inflation and deflation. Future versions will have a remote control device similar to a garage-door opener.