The initial event for normal erectile function is sexual stimulation. Subsequent to processing in the central nervous system neural impulses are conveyed along the spinal cord, exiting through the pelvic parasympathetic preganglionic nerves. These pelvic nerves form the pelvic plexus and send their message through first messenger, acetyl choline, to the cavernosal nerves. The cavernosal nerves enter erectile bodies (corpora cavernosa) (Figure 1). Here, their nerve endings release a second messenger, nitric oxide. Nitric oxide activates the enzyme guanylyl cyclase, which lyses guanosine triphosphate (GTP) to produce a third messenger, the intracellular cyclic guanosine monophosphate (cGMP). Ultimately, the result is a decrease of intracellular calcium and an opening of potassium channels with the resultant relaxation of vascular smooth muscle in the arteries, aterioles, and sinusoids of the corpora cavernosa. The sinusoids open and rapidly fill with blood. Finally, the distended sinusoids compress their drainage pathways (venules) against the fibroelastic covering of the cavernosal bodies (tunica albuginea) and trap the blood in cavernosal bodies. The combination of an increased inflow of blood into the penis and coincident markedly diminished outflow results in rapidly increasing intracavernosal pressure that ultimately approximates systolic pressure. At this pressure the penis has sufficient axial rigidity to permit vaginal penetration.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References Phase 2 and 3 trials reported minimal associated cardiac adverse effects, which occurred in 3% of patients taking sildenafil and in 3.5% of patients receiving placebos.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 (24) | Google ScholarSee all References Withdrawal of sexual stimulation causes a return of sympathetic tone and degradation of cGMP, predominantly by phosphodiesterase type 5 (PDE-5) within the trabecular smooth muscle.11x11Nehra, A. Intracavernosal therapy: when oral agents fail. Curr Urol Rep. 2001; 2: 468–472

Erectile dysfunction is defined as the inability to attain or maintain a penile erection sufficient for satisfactory sexual performance. Cases of ED may be classified as predominantly organic in nature, predominantly psychogenic, or mixed. Usual organic aetiologies are vasculogenic, hormonal, and neurogenic. Owing to the relationship of vasculogenic ED with CVD, it is important to distinguish men with predominantly vasculogenic ED from those with predominantly psychogenic ED or non-vasculogenic organic ED.


This form of therapy has a response rate of well over 70%. The sympathetic nervous system normally maintains the penis in a flaccid or non-erect state. All of the vasoactive drugs, when injected into the corpora cavernosae, inhibit or override sympathetic inhibition to encourage relaxation of the smooth muscle trabeculae. The rush of blood engorges the penile corpora cavernosae sinusoidal spaces and creates an erection.
A study published in May 2014 in The Journal of Sexual Medicine found that some men can reverse erectile dysfunction with healthy lifestyle changes, such as exercise, weight loss, a varied diet, and good sleep. The Australian researchers also showed that even if erectile dysfunction medication is required, it's likely to be more effective if you implement these healthy lifestyle changes.
The second way relates to the risk associated with the sexual activity in a patient with either overt or occult CVD. In this case, the diagnosis of ED should prompt an initial cardiovascular assessment based on the history and clinical examination in order to define the baseline risk according to (i) the likelihood of silent CAD18,31 (especially since ED patients have a high probability to have silent CAD) or to the stage of clinically evident CAD, (ii) other cardiovascular conditions either unrelated, or related to ED (e.g. heart failure, peripheral arterial disease).

Abstract | Full Text | Full Text PDF | PubMed | Scopus (25) | Google ScholarSee all References The Framingham Heart Study found a baseline risk of myocardial infarction in a healthy 50-year-old nonsmoking man to be approximately 1% per year, or 1 chance per million per hour.87x87Anderson, KM, Odell, PM, Wilson, PW, and Kannel, WB. Cardiovascular disease risk profiles. Am Heart J. 1991; 121: 293–298
There are so many potential reasons a man might develop erectile dysfunction (ED), it's nearly impossible to generalize the best ways to treat it. What works for one man may not work for another simply because they are having problems for different reasons. That said, it may encouraging to hear that there are a variety of options that may be considered, from psychological counseling to lifestyle changes, medications to treatments and devices.
Experimental in vivo studies have implicated central and peripheral neuropathy, impaired neurotransmission, and endothelial dysfunction in the pathogenesis of diabetic ED.26,27 Copulatory behavior and penile reflexes are uniformly impaired 4–12 months after the onset of diabetes in the BB rat.26,27 McVary et al.26 found that peripheral neuropathy accounts for only part of the dysfunctional findings, and that spinal sexual reflexes were also severely impaired.
Crossref | PubMed | Scopus (35) | Google ScholarSee all References Also, if lower blood pressure level was the primary etiology of ED, all classes of antihypertensive agents should be expected to have relatively similar effects on erectile function because of their efficacy in lowering pressure, which has not been seen.6x6Kloner, RA. Erectile dysfunction and cardiovascular risk factors. Hosp Pract (Off Ed). 2001; 36: 41–44 (49-51.)
The great majority of ED cases in diabetic men have a physical cause, such as neuropathy or circulatory problems. In some cases, however, the cause of ED is psychological, including depression, guilt, or anxiety. With a thorough exam, the doctor should be able to determine whether the ED is psychological or physical in nature. If the cause is psychological, your doctor may refer you to a psychiatrist, psychologist, sex therapist, or marital counselor. Do not view such a diagnosis as an insult. Most psychologically-based ED is easily and successfully treated.
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
Abstract | Full Text | Full Text PDF | PubMed | Scopus (30) | Google ScholarSee all References Erections result from relaxation of the corpora cavernosa, which is mediated either by increasing intracellular cyclic guanosine monophosphate (cGMP) or cyclic adenosine monophosphate or by inhibition of their degradation. Increased parasympathetic tone results in a decrease in norepinephrine release and an increase in the release of acetylcholine; subsequently, NO synthase activity increases, which releases NO from both endothelial cells and nonadrenergic, noncholinergic neurons.10x10Kloner, RA and Zusman, RM. Cardiovascular effects of sildenafil citrate and recommendations for its use. Am J Cardiol. 1999; 84: 11N–17N
Causes of ED may be of primary developmental origin or secondary. Lack of sex hormone in the early developmental stage of male children is the major cause of primary ED. The secondary cause of ED involves arteriosclerosis, diabetes or psychogenic disturbances. Other secondary factors may include hypertension, hyperlipidaemia, obesity and tobacco use. The primary causes of ED are beyond the scope of this review; we will not be discussing the neurovascular mechanisms pertaining to ED and will focus on the relationship between IHD and ED.
The vacuum constriction device consists of a vacuum cylinder, various sizes of tension rings, and a vacuum pump, either hand-operated or electric. The penis is placed in a cylinder to which a tension ring is attached. Air is evacuated from the cylinder by means of the pump, creating a vacuum, which produces the erection. The cylinder is removed, leaving the tension ring at the base of the penis to maintain the erection.

The drugs come in several strengths. Most men should start with a low to moderate dose. The dose can be adjusted depending on the results. Men with potential problems should always start with the lowest dose. Every man should avoid consuming alcohol before taking these drugs. Men who do not respond to a full dose on two or three different occasions should try other treatments.
Some blood pressure medicines can also cause erectile dysfunction. Thiazide diuretics and beta-blockers are most likely to cause problems, but this is not a common effect of these medicines and will not happen to everyone. If you are taking either of these medicines and are worried about erectile dysfunction, your GP may be able to change your medicines.
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.
Erectile dysfunction is common in the CVD patient. It is an important component of the quality of life and it also confers an independent risk for future CV events. The usual 3-year time frame between the onset of ED symptoms and a CV event offers an opportunity for risk mitigation. Thus, sexual function should be incorporated into CVD risk assessment for all men. Algorithms for the management of patient with ED have been proposed according to the risk for sexual activity and future CV events. A comprehensive approach to cardiovascular risk reduction (comprising of both lifestyle changes and pharmacological treatment) improves overall vascular health, including sexual function. Proper sexual counselling improves the quality of life and increases adherence to medication. Testosterone assessment may be useful for both diagnosis of ED, risk stratification and further management. There are issues to be addressed, such as whether PDE5 inhibition reduces CV risk. Management of ED requires a collaborative approach and the role of the cardiologist is pivotal.
The treatment of ED using TCM ties in with the treatment of late-onset hypogonadism (LOH). LOH occurs due to the breakdown in coordination between the heart and the kidneys, deficiencies of the spleen and kidney (yang), deficiencies of the liver and kidney (yin) and deficiencies of the kidney (yin and yang). The endocrine function of the pituitary and gonads becomes disordered with age due to a depression of overall function. This results in accumulation of free radicals and other toxins that cannot be relieved solely with male hormone supplementation. Warm yang can energize kidneys to benefit the body, remove toxins, invigorate qi and promote blood circulation. Free radicals are removed, blood fat regulated, cardio-cerebral blood flow improved and again the key here is to improve the function of the digestive, respiratory and endocrine systems, hence regulating the body in every aspect holistically (28).
Control your blood sugar through your diet. Eating a diabetes-friendly diet will help you better control your blood sugar levels and lessen the amount of damage to your blood vessels and nerves. A proper diet geared at keeping your blood sugar levels in check can also improve your energy levels and mood, both of which can help reduce the risk of erectile dysfunction. You may consider working with a dietitian who is also a certified diabetes educator to help adjust your eating style.
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.
Andersson said the results came as a surprise because erectile dysfunction is associated with an increased risk of heart disease in otherwise healthy men. However, previous studies have associated the use of PDE5 inhibitors with a decreased blood pressure in the left ventricle, which reduces the amount of work required to pump blood and therefore could help explain why the drugs might benefit people with heart failure. PDE5 inhibitors were initially developed to treat angina, a type of chest pain that results from constricted arteries.
Quassinoids isolated from Tongkat Ali have been reputed to be anti-tumor, anti-malarial, anti-amoebic and anti-inflammatory. Its leaves are used for washing itches, its fruits for the treatment of dysentery, its bark used as a vermifuge, the taproots used for treatment of hypertension and the root bark for treatment of diarrhea and fever. The roots extracts are used for sexual dysfunction, aging, malaria, cancer, diabetes, anxiety, aches, constipation, exercise recovery, fever, increased energy, increased strength, leukemia, osteoporosis, stress and syphilis. Animal studies done on middle age sex rats showed enhancement of the sexual qualities in terms of hesitation time among middle aged rats (46).
Another common reason for failures of oral therapy is the absence of sexual or genital stimulation prior to attempting sexual intercourse. These medicines facilitate an erection by increasing blood flow to the penis, but they do not act as an aphrodisiac or as an initiator of the erection. A man who is not “in the mood” or does not have adequate physical stimulation will not respond with an erection.
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