Sildenafil (Viagra) was the first oral phosphodiesterase type 5 (PDE5) inhibitor approved by the FDA in the United States for the treatment of erectile dysfunction (it is not approved for women). Sildenafil inhibits PDE5, which is an enzyme that destroys cGMP. By inhibiting the destruction of cGMP by PDE5, sildenafil allows cGMP to accumulate. The cGMP in turn prolongs relaxation of the smooth muscle of the corpora cavernosa. Relaxation of the corpora cavernosa smooth muscle allows blood to flow into the penis resulting in increased engorgement of the penis. In short, sildenafil increases blood flow into the penis and decreases blood flow out of the penis.
2 inability of the adult male to achieve or sustain a penile erection or, less commonly, to ejaculate after achieving an erection. Several forms are recognized. Functional impotence has a psychological basis. Organic impotence includes vasculogenic, neurogenic, endocrinic, and anatomical factors. Anatomical impotence results from physically defective genitalia. Atonic impotence involves disturbed neuromuscular function. Poor health, old or advancing age, drugs, smoking, trauma, and fatigue can induce impotence. Also called erectile dysfunction, impotency. impotent, adj.
Her remark was entirely destructive of poetry, since it was to the effect that poetry had nothing whatever to do with her; all her friends spent their lives in making up phrases, she said; all his feeling was an illusion, and next moment, as if to taunt him with his impotence, she had sunk into one of those dreamy states which took no account whatever of his existence.
Erectile dysfunction (ED) is the inability to get an erection or to keep one that's firm enough or that lasts long enough for a man to have a satisfying sexual experience. Occasional bouts of ED aren't unusual. In fact, as many as one in five men deal with erectile dysfunction to some degree. Symptoms, of course, are rather obvious. And while age can be a risk factor, so can medication use, health conditions, lifestyle factors (like smoking), and other concerns. Treatment is available and may involve prescriptions, habit changes, or other options.
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Impotence, or erectile dysfunction, is the inability of a male to attain and keep an erection sufficiently firm to engage in or complete sexual intercourse. Although it is more common in older men, impotence can occur at any age. Impotence is not a normal consequence of aging. About 70% of erectile dysfunction is due to diseases such as diabetes and atherosclerosis, another 10% to 20% is due to psychological factors, and the remaining percentage is related to medications, lifestyle factors, and injury (Source: NIDDK).

The observation that TRT enhances the efficacy of PDE5 inhibitors in hypogonadal men taking these therapies with suboptimal response to the PDE5 inhibitors alone has been reported.33 In addition, investigators have demonstrated that TRT in hypogonadal men can improve erectile function even without the benefit of PDE5 inhibitors.33 In addition, guidelines for managing ED in hypogonadal men by the European Association of Urology recommend controlling the man to a eugonadal state prior to initiation of PDE5 inhibitor therapy.36 Testosterone measurement consists of a serum specimen which should be ideally obtained in the morning because of the normal diurnal variation of testosterone which is at its peak in the morning. Since TRT is relatively safe, and men can potentially see an improvement in erectile function, it seems prudent to consider this issue when presented with a patient suffering from ED.

Counselling or sex therapy (58% of people find this works for them) –mind-related causes of erectile dysfunction can affect anyone. They are more likely if you experience erectile dysfunction at a younger age. Talking to a counsellor or therapist can help some people overcome erectile dysfunction related to these problems, possibly for good. They can also help you if your erectile dysfunction is causing you stress, as this can make matters worse.
ED can also occur among younger men. A 2013 study found that one in four men seeking their first treatment for ED were under the age of 40. The researchers found a stronger correlation between smoking and illicit drug use and ED in men under 40 than among older men. That suggests that lifestyle choices may be a main contributing factor for ED in younger men.

Nocturnal penile tumescence testing (NPT) may be useful in distinguishing mental from physical impotence. This test involves the placement of a band around the penis that you would wear during two or three successive nights. If an erection occurs, which is expected during rapid eye movement (REM) sleep, the force and duration are measured on a graph. Inadequate or no erections during sleep suggests an organic or physical problem, while a normal result may indicate a high likelihood of emotional, psychological, or mental causes.

The idea of using low-energy shock waves to treat erectile dysfunction comes from studies that show that these types of shocks help heart blood vessels regrow, a process called revascularization. Shock wave therapy may also work on the penis, and there have been some promising results, but it’s not currently an approved ED treatment. "It’s similar to the type of shock waves used to break up kidney stones, and it may cause revascularization,” says Bennett. “However, there are not yet any good controlled studies to recommend it to patients."


The medications are extremely effective, which is very good. And the medications are, for the most part, extremely well-tolerated. But there are, like with any medications, a potential downside. The one absolute downside to the use of any of these erection what we call PDE5 medications is if a patient is using a nitroglycerin medication. And nitroglycerins are used for heart disease and for angina, for the most part, although there are some recreational uses of nitrites. And that’s important because your blood vessels will dilate and your blood pressure will drop. And that is an absolute contraindication.
Erectile dysfunction (ED) is the inability to get an erection or to keep one that's firm enough or that lasts long enough for a man to have a satisfying sexual experience. Occasional bouts of ED aren't unusual. In fact, as many as one in five men deal with erectile dysfunction to some degree. Symptoms, of course, are rather obvious. And while age can be a risk factor, so can medication use, health conditions, lifestyle factors (like smoking), and other concerns. Treatment is available and may involve prescriptions, habit changes, or other options.

3. Are there physical causes of erectile dysfunction? Erectile dysfunction may be a symptom of underlying medical conditions, which if not detected may cause further medical problems. A prior history of cigarette smoking, heart attacks, strokes, and poor circulation in the extremities (for example, intermittent claudication or cramping in your leg[s] when you walk) suggest atherosclerosis as the cause of the erectile dysfunction. Loss of sexual desire and drive, lack of sexual fantasies, gynecomastia (enlargement of breasts), and diminished facial hair suggest low testosterone levels. A prior history of pelvic surgery or radiation and trauma to the penis/pelvis/perineum can cause problems with the nerves and blood vessels. Symptoms of intermittent claudication of the lower extremities with exercise may suggest a vascular problem as a cause of the erectile dysfunction.

Melanocortin receptor agonists were found to induce erections serendipitously. A study investigating the dermatologic use of Melanotan-II (MT-II) was found to generate erections unexpectedly leading to the development of MTII derivatives for ED treatment (120). MT-II was initially used to induce pigment changes in the skin for artificial tanning but has been suspected to induce melanoma, however (121).

Psychotherapy, marital counseling, or sex therapy may be helpful in treating cases of impotence that have psychological or emotional causes. A range of other treatments exists for cases of impotence that arise from purely physiological causes. These treatments include vacuum devices, penile injections, and penile implants. These mechanical or physically invasive approaches have largely been superseded, however, by the drug sildenafil citrate (trade name Viagra), which is taken in pill form. This drug works by enhancing the effects of nitric oxide, a chemical that, upon sexual stimulation, is normally released to widen the blood vessels supplying the penis. The increased flow of blood through those vessels into certain tissues in the penis causes an erection. See also sexual dysfunction.
In some cases, nocturnal penile tumescence testing is performed to find out whether the man has erections while asleep. Healthy men usually have about four or five erections throughout the night. The man applies a device to the penis called a Rigiscan before going to bed at night, and the device can determine whether he has had erections. (If a man is able to have normal erections at night, this suggests a psychological cause for his impotence.)
The liver is the largest gland and organ in the body. There are a variety of liver diseases caused by liver inflammation, scarring of the liver, infection of the liver, gallstones, cancer, toxins, genetic diseases, and blood flow problems. Symptoms of liver disease generally do not occur until the liver disease is advanced. Some symptoms of liver disease include jaundice, nausea and vomiting, easy bruising, bleeding excessively, fatigue, weakness, weight loss, shortness of breath, leg swelling, impotence, and confusion. Treatment of diseases of the liver depends on the cause.
Alprostadil injections, which produce an erection in five to 20 minutes that lasts for about an hour. Patients use a fine needle to inject alprostadil (commonly known by the brand names Caverject Impulse and Edex) into the base or side of the penis. Side effects can include bleeding or fibrous tissue formation at the injection site as well as prolonged erection, according to the Mayo Clinic.

Infection is a concern after placement of a penile prosthesis and is reported as a complication in up to 20% of men undergoing placement of a penile prosthesis. If the device becomes infected more commonly, it needs to be removed. Another prosthesis can be placed after the infection is treated and the penile tissues have healed, but it is a difficult surgery. Erosion of the prosthesis, whereby it compresses through the corporal tissue, into the urethra may occur. Symptoms include pain, blood in the urine, discharge, abnormal stream, and malfunction of the prosthesis. If the prosthesis erodes, it will need to be removed. A catheter is placed to allow the urethra to heal.


Positron emission tomorgraphy (PET), and functional magnetic resonance imaging (fMRI) have led to a greater understanding to which center are activated during arousal. These imaging studies measure increases in cerebral blood flow or changes in cerebral activity on a real-time basis. Studies are performed when male subject are aroused by visual cues (usually sexual explicit photos or videos) and compared to images obtained during exposure to sexually neutral cues differences can be measured. Several studies have identified that the inferior frontal lobes, inferior temporal lobes and insular gyrus, and occipital lobes are involved with processing arousal cues, although each are likely to process different stimuli (20-23).

What you need to know about delayed ejaculation Delayed ejaculation is a sexual disorder that can be distressing for a man and his partner and may disrupt a relationship. There are many reasons why delayed ejaculation occurs, including tissue damage, age, drugs, and the side effects of medication. They may be physiological or psychological. Find out how to get help. Read now
As blood flows into the penis, the corpora cavernosa swell, and this swelling compresses the veins (blood vessels that drain the blood out of the penis) against the tunica albuginea. Compression of the veins prevents blood from leaving the penis. This creates a hard erection. When the amount of cGMP decreases by the action of a chemical called phosphodiesterase type 5 (PDE5), the muscles in the penis tighten, and the blood flow into the penis decreases. With less blood coming into the penis, the veins are not compressed, allowing blood to drain out of the penis, and the erection goes down.

…that relieve erectile dysfunction (impotence) in men. Two common commercially produced PDE-5 inhibitors are sildenafil (sold as Viagra) and vardenafil (Levitra). PDE-5 inhibitors work by blocking, or inhibiting, the action of phosphodiesterase-5 (PDE-5), an enzyme naturally present in the corpus cavernosum, the spongy erectile tissue of the penis. Under…

Yohimbine: The main component of an African tree bark, yohimbine is probably one of the most problematic of all natural remedies for ED. Some research suggests that yohimbine can improve a type of sexual dysfunction that is linked with a drug used to treat depression. However, studies have linked yohimbine to a number of side effects, which can include anxiety, increased blood pressure, and a fast, irregular heartbeat. Like all natural remedies, yohimbine should only be used after advice and under supervision from a doctor.
Injection therapy involves injecting a substance into the penis to enhance blood flow and cause an erection. The Food and Drug Administration (FDA) approved a drug called alprostadil (Caverject) for this purpose in July of 1995. Alprostadil relaxes smooth muscle tissue to enhance blood flow into the penis. It must be injected shortly before intercourse. Another, similar drug that is sometimes used is papaverine—not yet been approved by the FDA for this use. Either drug may sometimes cause painful erections or priapism (uncomfortable, prolonged erections) that must be treated with a shot of epinephrine.

A variety of personal habits and lifestyle choices have been linked to ED. In some ways, this is a good thing, since habits can be broken and choices reconsidered. What's more, many of the lifestyle factors that contribute to sexual problems are ones that affect overall health and well-being, both physical and mental. Addressing these factors, therefore, can have benefits beyond improving erectile dysfunction.
The association of CVD and ED was noted in 1997 as one analysed the results of the MMAS. In this landmark study, 1709 men aged 40–70 years were enrolled between 1987 and 1989. A follow-up some 10 years later revealed a striking relationship between ED and CVD. In this study, it became clear that the risk factors for ED were very similar to those of CVD, such as diabetes mellitus, smoking and dyslipidaemia.18
Trauma to the pelvic blood vessels and nerves is another potential factor in the development of ED. Bicycle riding for long periods has been implicated, so some of the newer bicycle seats have been designed to soften pressure on the perineum (the soft area between the anus and the scrotum). Certainly, history of pelvic bone fracture, as well as previous pelvic surgery (orthopedic, vascular, colon-rectum, and prostate) may result in injury to the arteries or nerves that go to the penis.
It is important for clinicians prescribing these drugs to make the patient aware of the action of the drugs especially the fact that they do not result in an immediate erection, and that they do not cause an erection without sexual stimulation. There is frequently a great expectation when men begin using these drugs and it is wise to temper their enthusiasm and explain they do not work immediately, and may not work every time, but also let the patient know that if these drugs do not work, there are other options.
For many of the 30 million Americans affected by erectile dysfunction, Viagra, Levitra, and Cialis are the first line of ED treatment — and they’re successful for about 80 percent of men. These drugs, called phosphodiesterase-5 inhibitors, are approved by the U.S. Food and Drug Administration (FDA) and work by increasing blood flow to an erection. Common side effects include nasal congestion and headache. Note: If you take nitroglycerin pills for heart disease, you won’t be able to take ED pills, as they can cause a dangerous drop in blood pressure.

The role of the endothelium in ED has been noted for a number of years and the overlapping of ED and other conditions, especially coronary heart disease, CVD, affecting endothelial function/dysfunction, is clearly present. The endothelial cell is now known to affect vascular tone and impact the process of atherosclerosis, and impacting ED, CVD and peripheral vascular disease.16
Other form of sexual dysfunction, such as premature ejaculation and loss of libido (decreased sexual desire), are also very common. The NHSLS found that 28.5% of men 18-59 years of age reported premature ejaculation, and 15.8% lacked interest during the past year. An additional 17% reported anxiety about sexual performance, and 8.1% indicated a lack of pleasure from sexual activity.
Instead of the hesitation with which he had accosted the cardinal a quarter of an hour before, there might be read in the eyes of the young king that will against which a struggle might be maintained, and which might be crushed by its own impotence, but which, at least, would preserve, like a wound in the depth of the heart, the remembrance of its defeat.

The downside to these prostheses includes the standard risks of surgery, the very low risk of infection — less than 2 percent in most patients, slightly higher in diabetics — and a slight drop in penis length versus a natural erection or other ED treatments. Also, unlike with other methods, any hope for a natural erection is abolished once a pump is implanted. The cost for surgical options varies, and insurance coverage is typically good.

There have been rare reports of priapism (prolonged and painful erections lasting six or more hours) with the use of PDE5 inhibitors. Patients with blood cell diseases such as sickle cell anemia, leukemia, and multiple myeloma have higher than normal risks of developing priapism. Untreated priapism can cause injury to the penis and lead to permanent impotence. Therefore, if your erection lasts four hours, you should seek emergency care.
Cardiovascular diseases: The most common cause of cardiovascular diseases in the United States is atherosclerosis, the narrowing and hardening of arteries that reduces blood flow. Atherosclerosis (a type of vascular disease) typically affects arteries throughout the body; hypertension, high blood cholesterol levels, cigarette smoking, and diabetes mellitus aggravate atherosclerosis. Hardening of the arteries to the penis and pelvic organs, atherosclerosis, causes insufficient blood flow into the penis. There is a close correlation between the severity of atherosclerosis in the coronary arteries and erectile dysfunction. For example, men with more severe coronary artery atherosclerosis (hardening of the arteries in the heart) also tend to have more erectile dysfunction than men with mild or no coronary artery atherosclerosis. Some doctors suggest that men with new onset erectile dysfunction undergo evaluation for silent coronary artery diseases (advanced coronary artery atherosclerosis that has not yet caused angina or heart attacks).
Moemen et al. compared the effectiveness and satisfaction associated with use of several ED therapies including sildenafil alone, intracavernosal injections (ICI) followed by sildenafil after ICI discontinuation and vacuum erections devices (VED) followed by sildenafil therapy after VED discontinuation (60). Seventy percent of men receiving vasoactive medications preferred sildenafil to ICI, even though rigidity was superior in the ICI group. All men using VEDs were dissatisfied with that form of therapy.
The physical examination can reveal clues for physical causes of erectile dysfunction. A doctor will perform an assessment of BMI and waist circumference to evaluate for abdominal obesity. A genital examination is part of the evaluation of erectile dysfunction. The examination will focus on the penis and testes. The doctor will ask you about penile curvature and will examine the penis to see if there are any plaques (hard areas) palpable. The doctor will examine the testes to make sure they are in the proper location in the scrotum and are normal in size. Small testicles, lack of facial hair, and enlarged breasts (gynecomastia) can point to hormonal problems such as hypogonadism with low testosterone levels. A health care provider may check pulses in your groin and feet to determine if there is a suggestion of hardening of the arteries that could also affect the arteries to the penis.

SD in MS can be classified into three categories. Primary SD is due directly due to MS-related neurological deficits, secondary SD is related to physical impairments and symptoms or drugs used for MS treatment, and tertiary SD is due to the psychological, social and cultural problems attributed to MS (38). These classifications are important, and underscore the importance of addressing all the issues leading to SD not just the neurologic impairment.
Erections occur in response to tactile, olfactory, and visual stimuli. The ability to achieve and maintain a full erection depends not only on the penile portion of the process but also on the status of the peripheral nerves, the integrity of the vascular supply, and biochemical events within the corpora. The autonomic nervous system is involved in erection, orgasm, and tumescence. The parasympathetic nervous system is primarily involved in sustaining and maintaining an erection, which is derived from S2-S4 nerve roots.
What you need to know about STDs Sexually transmitted diseases (STDs) are infections that are passed on from one person to another through sexual contact. There are many STDs, including chlamydia, genital warts, syphilis, and trich. This article looks at some of the most common STDs, the symptoms, and how to avoid getting or passing an STD one on. Read now
Because the burning side effect is triggered by alprostadil, the formulations with the least alprostadil — tri-mix and certain versions of bi-mix — could work for men who experience burning with the single-drug formula. But some men might choose alprostadil alone because the multi-drug cocktails can cost more and must be dispensed by a compounding pharmacy — one that is authorized to mix medications on site — which could mean the added hassle of a long drive to pick up the drug.
High cholesterol and triglyceride levels increase the risk of cardiovascular disease. Getting your cholesterol and triglyceride levels in an optimal range will help protect your heart and blood vessels. Cholesterol management may include lifestyle interventions (diet and exercise) as well as medications to get your total cholesterol, LDL, HDL, and triglycerides in an optimal range.

Sexual stimulation causes the release of neurotransmitters from cavernosal nerve endings and relaxation factors from endothelial cells lining the sinusoids. NOS produces NO from L-arginine, and this, in turn, produces other muscle-relaxing chemicals, such as cGMP and cyclic adenosine monophosphate (cAMP), which work via calcium channel and protein kinase mechanisms (see the image below). This results in the relaxation of smooth muscle in the arteries and arterioles that supply the erectile tissue, producing a dramatic increase in penile blood flow.


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