Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References Phosphodiesterase type 5 is found predominantly in the smooth muscle of the corpora cavernosa but can be found in smaller quantities in platelets and other vascular smooth muscle.56x56Wallis, RM, Corbin, JD, Francis, SH, and Ellis, P. Tissue distribution of phosphodiesterase families and the effects of sildenafil on tissue cyclic nucleotides, platelet function, and the contractile responses of trabeculae carneae and aortic rings in vitro. Am J Cardiol. 1999; 83: 3C–12C

Diuretics: Diuretics are also referred to as water pills. They can make the flow of blood to your penis less intense. This makes getting an erection difficult. Diuretics are also known to lower zinc levels, which can decrease the amount of testosterone your body makes. In turn, this can decrease your sex drive. It may also affect your muscle contraction.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (46) | Google ScholarSee all References Sedentary patients with a history of cardiac disease and patients with unstable angina or advanced congestive heart failure should undergo a full medical evaluation before resuming sexual activity.80x80Muller, JE. Triggering of cardiac events by sexual activity: findings from a case-crossover analysis. Am J Cardiol. 2000; 86: 14F–18F
Low intracavernosal nitric oxide synthase levels are found in people with diabetes, smokers, and men with testosterone deficiency. Interference with oxygen delivery or nitric oxide synthesis can prevent intracavernosal blood pressure from rising to a level sufficient to impede emissary vein outflow, leading to an inability to acquire or sustain rigid erection. Examples include decreased blood flow and inadequate intracavernosal oxygen levels when atherosclerosis involves the hypogastric artery or other feeder vessels and conditions, such as diabetes, that are associated with suboptimal nitric oxide synthase activity.
Luckily, awareness of ED as a significant and common complication of diabetes has increased in recent years, mainly because of increasing knowledge of male sexual function and the rapidly expanding armamentarium of novel treatments being developed for impotence. Studies of ED suggest that its prevalence in men with diabetes ranges from 35–75% versus 26% in general population. The onset of ED also occurs 10–15 years earlier in men with diabetes than it does in sex-matched counterparts without diabetes.
Faced with concern about ED pills and the heart, the FDA has urged caution in patients who have suffered heart attacks, strokes, or serious disturbances of the heart's pumping rhythm in the previous six months, in men with a history of congestive heart failure or unstable angina, and in men with low blood pressure or uncontrolled high blood pressure (above 170/110 mm Hg). Because certain medications can boost the blood levels of these drugs, men taking erythromycin or certain antifungal or anti-HIV medications should use only low-dose PDE-5 inhibitors. Reduced dosage is also important for men with advanced age and for those with significant kidney or liver disease.
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
There are two kinds of surgery for ED: one involves implantation of a penile prosthesis; the other attempts vascular reconstruction. Expert opinion about surgical implants has changed during recent years; today, surgery is no longer so widely recommended. There are many less-invasive and less-expensive options, and surgery should be considered only as a last resort.
Phosphodiesterase Inhibitors. The cornerstone of first-line therapy is the PDE-5 inhibitor. No other class of oral agents approaches the efficacy of PDE-5 inhibitors. Yohimbine, trazodone, phentolamine, L-arginine, and OTC herbal remedies have been used with very limited success. The superiority of yohimbine over placebo in the treatment of organic ED is a matter of dispute.9 A recent trazodone study failed to detect any difference between trazodone and placebo on sexual function.10 Oral phentolamine, although available in Mexico, has not been approved by the US FDA for the treatment of ED. Apomorphine, a central dopaminergic receptor drug, has recently been voluntarily withdrawn from FDA consideration for the treatment of ED. The efficacy of ginkgo biloba and Korean red ginseng has yet to be demonstrated by randomized, placebo-controlled trials.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (395) | Google ScholarSee all References Sildenafil has no effect on bleeding time or prothrombin time when used either alone or in patients taking aspirin or warfarin.61x61Nehra, A, Colreavy, F, Khandheria, BK, and Chandrasekaran, K. Sildenafil citrate, a selective phosphodiesterase type 5 inhibitor: urologic and cardiovascular implications. World J Urol. 2001; 19: 40–45
If the cause is believed to be organic but not hormonal, or if the patient defers psychological intervention, he can be offered the VCD or oral drug therapy. EDDM patients on organic nitrates or who have experienced or are concerned about potential adverse reaction to PDE-5 inhibitors are suitable candidates for the VCD. The VCD induces functional rigidity in 75% of patients with diabetes with autonomic neuropathy. Some patients or their partners may reject or discontinue the use of the VCD because it induces an unnatural erection, causes bruising and numbness of the penis, and or inhibits antegrade ejaculation.8

Like the case of untreated hypertensive patients, evaluation of sexual dysfunction in hypertensive patients under antihypertensive regime, should primarily exclude other concomitant diseases and pharmaceutical agents. Consecutively, a competent physician with advanced communicational skills should try to “discover” medically induced erectile dysfunction since a vast majority of patients being under complex antihypertensive regimes usually attribute the undesirable effect to normal aging thus not relating it to their current medication. Moreover, even physicians seldom report the cases of sexual dysfunction associated with certain medications. When medically induced sexual dysfunction is finally disclosed and a shift in medication is deemed necessary, b-blockers along with diuretics should generally be the first categories to be changed, unless they are deemed absolutely indicated for the individual patient. Ideally, an ARB could constitute the mainstay of therapy in these cases. If sexual dysfunction still persists, then more effective remedies should be elected paving the way for the introduction of phosphodiesterase-5 inhibitors (PDE-5).


Abnormalities in the vascular, neural, endocrine, muscular, or psychiatric systems can result in ED.2,3 EDDM is due to multisystemic disease. Atrophy or apoptosis of cavernosal smooth muscle can occur due to loss of Bcl-2 expression in cavernosal smooth muscle and lead to ED. Abnormal amounts of advanced glycation end products is a common occurrence. These chemicals may have an effect on potassium channels that facilitate intracellular calcium release and subsequent cavernosal smooth muscle relaxation. Connective tissue synthesis is increased due to transforming growth factor-beta. The decrease in smooth muscle and the increase in collagen decreases the compliance of the erectile tissue. Neuropathic damage to both the somatic and autonomic nerves has been clearly defined in DM. Partial occlusion of the pelvic or intracavernosal arteries, hypogonadotropic hypogonadism, and depression associated with a chronic illness (DM) can all play a primary or secondary role in the development of EDDM. On a molecular level, studies have demonstrated decreased levels of endothelial and neuronal nitric acid synthase (NS) and decreased cavernosal artery and sinusoidal response to nitric oxide. Abnormalities in nitric oxide rapidly render the functional syncytium of the corpora cavernosa unable to synchronously relax. As the patient with diabetes ages, the concentration of constrictors, including endothelin, prostanoids, and possibly angiotensin, increases as the production of the relaxants, including nitric oxide, vasointestinal peptide, and prostacyclin, decreases.
Erectile dysfunction (ED) is a common sexual problem affecting many men irrespective of cultures, beliefs and nationalities. While medical therapy for ED has been revolutionized by the advent of oral phosphodiesterase type 5 inhibitors and intracavernosal injection of vasoactive agents, recent technological advances such stem cell therapy, low intensity shock wave and newer generation of penile prosthesis implant offer hope to men who do not respond to conventional medical therapy. In contrast, traditional and complementary medicine (TCM) focuses on the restoration and better overall bodily regulation with the use of various herbal and animal products as well as exercises to invigorate qi (energy) in vital organs. Western medicine involves an analysis of ED symptom and underlying causes that contribute to ED, while TCM emphases the concept of holism and harmonization of body organs to achieve natural sexual life. The following article reviews our current understanding regarding the philosophical approach, and evaluates the evidence surrounding various ED therapies between mainstream Western Medicine and TCM.
Abnormalities in the vascular, neural, endocrine, muscular, or psychiatric systems can result in ED.2,3 EDDM is due to multisystemic disease. Atrophy or apoptosis of cavernosal smooth muscle can occur due to loss of Bcl-2 expression in cavernosal smooth muscle and lead to ED. Abnormal amounts of advanced glycation end products is a common occurrence. These chemicals may have an effect on potassium channels that facilitate intracellular calcium release and subsequent cavernosal smooth muscle relaxation. Connective tissue synthesis is increased due to transforming growth factor-beta. The decrease in smooth muscle and the increase in collagen decreases the compliance of the erectile tissue. Neuropathic damage to both the somatic and autonomic nerves has been clearly defined in DM. Partial occlusion of the pelvic or intracavernosal arteries, hypogonadotropic hypogonadism, and depression associated with a chronic illness (DM) can all play a primary or secondary role in the development of EDDM. On a molecular level, studies have demonstrated decreased levels of endothelial and neuronal nitric acid synthase (NS) and decreased cavernosal artery and sinusoidal response to nitric oxide. Abnormalities in nitric oxide rapidly render the functional syncytium of the corpora cavernosa unable to synchronously relax. As the patient with diabetes ages, the concentration of constrictors, including endothelin, prostanoids, and possibly angiotensin, increases as the production of the relaxants, including nitric oxide, vasointestinal peptide, and prostacyclin, decreases.

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.
In TCM, the meridian system is thought to represent a path through which the life energy qi flows and as discussed in earlier section, the “Jing” (kidney) qi plays an important role in penile erection. Acupuncture helps to correct the imbalances to relieve physical symptoms by stimulating various meridian points. The Shensu (BL23), Zusanli (ST36) and Neiguan (PC6) points represents important acupoints for penis stimulation and thus has a positive homeostatic effect on the autonomic nervous system, and potentially modulate NO release (55,56). While some studies have showed up to a third of patients reported improvement in penile erection and sexual activity, systematic review showed insufficient data to conclude that acupuncture is an effective intervention for treating ED (56,57). Therefore, further scientific research is required to investigate whether there are specific benefits of acupuncture for men with ED before acupuncture can be accepted as evidence-based practice.

Medicines known as PDE5 inhibitors can help two-thirds of men with ED. These include Viagra (sildenafil), Cialis (tadalafil) and Levitra (vardenafil). You may need to take several doses over time before they work properly, and you may need to adjust the dose. National guidelines say you can be prescribed these drugs from six months after a heart attack, providing your condition is stable.

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
Abstract | Full Text | Full Text PDF | PubMed | Scopus (46) | Google ScholarSee all References The significant sympathetic discharge associated with sexual intercourse may contribute to the development of arrythmias in susceptible patients.81x81Drory, Y, Fisman, EZ, Shapira, Y, and Pines, A. Ventricular arrhythmias during sexual activity in patients with coronary artery disease. Chest. 1996; 109: 922–924
Some doctors prefer to start a man on the lowest dose of an oral medicine and increase the dose until an effective one is found. Others prefer to start with the highest dose and go to a lower dose only if a man complains of side effects. In either case, it’s important for a man to communicate with his doctor to let him know how the dose he’s using is working.
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