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.

If you have symptoms of ED, it’s important to check with your doctor before trying any treatments on your own. This is because ED can be a sign of other health problems. For instance, heart disease or high cholesterol could cause ED symptoms. With a diagnosis, your doctor could recommend a number of steps that would likely improve both your heart health and your ED. These steps include lowering your cholesterol, reducing your weight, or taking medications to unclog your blood vessels.
High blood pressure, otherwise known as hypertension, can contribute to erectile dysfunction (ED). Some of the medications used to treat high blood pressure can cause ED as well. According to the authors of one study, about 30 percent of men with high blood pressure also have had ED. Finding a medication that treats high blood pressure without causing ED is a goal of many men.
In years past, before nitric oxide and its role in the erectile response was appreciated, testosterone was used to treat sexual dysfunction in men. It proved a partial success as a standalone therapy, resulting in improved erectile potency in 40–60% of men with low-to-normal testosterone levels. The likelihood of success increased, however, if starting testosterone levels were low (usually defined as below 300 ng/dL), in which case improved erections were experienced by as many as 65% of men, compared with 16.7% receiving placebo; topical testosterone preparations were also noted to be superior to oral replacement or injections.21 These findings were confirmed by another study that showed testosterone produced modest improvements in erectile function and libido in men with low-to-normal testosterone levels.22
Hypertension can affect endothelial function in many ways. It can reduce endothelium-dependent vasodilatation by increasing the vasoconstrictor tone as a result of increased peripheral sympathetic activity.41–43 Another mechanism is hypertension-induced increase in cyclooxygenase activity that leads to an increase in reactive oxygen species; these in turn damage endothelial cells and disrupt their function.44–46 In some cases, endothelial NO synthase (eNOS) gene variations may relate to hypertension-associated endothelial dysfunction.6
Finally, prevalence rates will be affected by whether the study population is accrued from a single hospital/clinic setting or from a more general population of men with diabetes. For example, Siu et al.4 studied 500 Chinese diabetic men (of which 97% had type 2 disease) seen at a single medical clinic in Hong Kong during 1999 and found the overall prevalence of ED to be 63.6%. Contrast this to Fedele et al.,5 who studied 9,756 diabetic men accrued from 178 diabetes centers in Italy. Among the 8,373 men with type 2 diabetes, only 37% reported ED, considerably less than in the Chinese study.
Diabetes occurs when you have too much sugar circulating in your bloodstream. There are two main types of diabetes: type 1 diabetes, which affects less than 10 percent of those who have diabetes, and type 2 diabetes, which accounts for over 90 percent of diabetes cases. Type 2 diabetes often develops as a result of being overweight or inactive. Approximately 30 million Americans have diabetes, and about half of them are men.

Intracavernosal and intraurethral injections are second-line therapy for patients with ED. Alprostadil is the agent most commonly used for intracavernosal injections. The main adverse effects of intracavernosal injections are painful erection, priapism and development of scarring at the injection site.73 Alprostadil is also available as a topical cream in patients who cannot tolerate injections.75


Abstract | Full Text | Full Text PDF | PubMed | Scopus (328) | Google ScholarSee all References Their mean resting systolic and diastolic blood pressure levels decreased by 6% and 11%, respectively, compared with baseline. These patients also experienced a mild decrease in mean resting right atrial pressure, pulmonary artery pressure, pulmonary artery occlusion pressure, and cardiac output. However, the hemodynamic response to exercise was preserved. Phase 2 and 3 trials showed no difference in the rate of adverse events between sildenafil and placebo in patients being treated with antihypertensive medications. The effects of sildenafil on blood pressure level were similar in patients who were taking antihypertensive medications compared with those who were not. In healthy volunteers, no consistent or significant doserelated electrocardiographic (ECG) changes were noted at 1 and 2 hours after doses of sildenafil ranging from 1.25 to 200 mg.3x3Zusman, RM, Morales, A, Glasser, DB, and Osterloh, IH. Overall cardiovascular profile of sildenafil citrate. Am J Cardiol. 1999; 83: 35C–44C
medicines called alpha-blockers such as Hytrin (terazosin
HCl), Flomax (tamsulosin HCl), Cardura (doxazosin
mesylate), Minipress (prazosin HCl), Uroxatral (alfuzosin HCl),
 Jalyn (dutasteride and tamsulosin HCl), or Rapaflo (silodosin).
Alpha-blockers are sometimes prescribed for prostate
problems or high blood pressure. In some patients, the use
of Sildenafil with alpha-blockers can lead to a drop in blood pressure or to fainting
One study the authors reviewed measured these changes in middle-aged men with and without coronary artery disease. This study found that the peak heart rate during intercourse was lower than heart rates measured during the patients' normal daily activities. The study participants' peak oxygen consumption levels during intercourse were moderate -- comparable to their oxygen consumption levels during moderate activities such as walking on level ground at 3 to 4 miles per hour, climbing stairs slowly or doing general housework such as vacuuming.
The recommended dosage of sildenafil is 50 mg/day, usually taken 1 hour before sexual activity. This dose may be increased to 100 mg or decreased to 25 mg based on side effects.6 PDE5 inhibitors also have a beneficial effect in the treatment of heart failure with reduced ejection fraction as well as pre- and post-capillary pulmonary hypertension. The use of PDE5 inhibitors in the treatment of right heart failure and left ventricular failure associated with combined pre- and post-capillary pulmonary hypertension has been well studied.71,72
PubMed | Google ScholarSee all References Interestingly, this study found no association between erectile function and the number of years or packs per day of cigarette use. In contrast, a study of 314 current smokers with ED found that the number of cigarettes smoked inversely correlated with penile rigidity as measured by nocturnal penile tumescence.27x27Hirshkowitz, M, Karacan, I, Howell, JW, Arcasoy, MO, and Williams, RL. Nocturnal penile tumescence in cigarette smokers with erectile dysfunction. Urology. 1992; 39: 101–107
The Massachusetts Male Aging Study of 1,290 men, aged 40–70 years, has documented the extraordinarily high prevalence of erectile dysfunction among aging men: 50% of men at 50 years of age, and 70% by age 70 have erectile dysfunction.2 Furthermore, a recent Italian study of men with severe heart disease has uncovered an astounding 93% with erectile dysfunction 24 months before their heart attack or onset of heart disease symptoms.3
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

Besides mammalian organs, insects and arthropods are also consumed as aphrodisiacs in Eastern medicine. These include scorpions, spiders, beetles, flies and other bugs (32). Penile erections can be observed following administration of neurotoxins as it causes repetitive firing of the somatic, sympathetic and parasympathetic neurons, resulting in autonomic and neuromuscular over-excitation. Scorpions are often used as an ingredient found in herbal wines. However, there is a general lack of literature regarding the consumption of scorpion neurotoxins for potency.
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. Hypertension per se and antihypertensive drug therapy may contribute to the development of erectile dysfunction in patients with arterial hypertension. The management of erectile dysfunction in hypertensive patients is tricky and should take into account the different effects of antihypertensive drug categories on erectile function. 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, PDE-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 and better characterize the relevant risk with obvious benefits for cardiovascular disease prevention.

Another risk factor is that men with type 2 diabetes may produce less than normal amounts of testosterone, a condition called hypogonadism. A 2007 study found that one-third of men with type 2 diabetes had low testosterone levels. Those men were also more likely to have ED, though the link may have to do with weight, not diabetes per se. Being overweight or obese is a risk factor for hypogonadism.
Despite its limitations in detecting CVD without significant stenosis, EST (with or without imaging) can further define the cardiovascular risk in patients with ED and no overt CAD and may be particularly helpful for identifying silent CAD in patients with diabetes. Chemical stress tests are appropriate for patients who cannot complete an EST or in whom ECG is non-interpretable. In patients with established CVD, an interpretable EST is mandatory in the indeterminate risk category and is at the discretion of the cardiologist in the low risk category (Table 3B), since it determines exercise ability and estimates cardiovascular risk associated with sexual activity.
Erectile dysfunction is a common occurrence in men with diabetes. The incidence of erectile dysfunction increases progressively with age, from 5% in men age 20 to 75% in men over age 65. The cause of erectile dysfunction in men with diabetes is usually related to a decrease in the blood supply to the penis as well as to injury to the nerves that are responsible for the erection mechanism. A decrease in testosterone production has also been identified as the cause in some men with diabetes.
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