Erectile Dysfunction
Erectile dysfunction (impotence) is the inability to achieve or maintain an erection.
Every man is occasionally unable to achieve an erection; this is normal. Erectile dysfunction occurs when the problem is frequent or continuous.
Erectile dysfunction can range from mild to severe. A man with mild erectile dysfunction may occasionally achieve a full erection, but more often he achieves an erection that is inadequate for penetration. He may frequently be unable to achieve an erection at all. A man with severe erectile dysfunction is rarely able to achieve an erection.
Erectile dysfunction becomes more common with age but is not part of the normal aging process. About half of men 65 years of age and three fourths of men 80 years of age have erectile dysfunction.
Causes
To achieve an erection, the penis needs both an adequate inflow of blood and a slowing of blood outflow. (see Section 21, Chapter 237) Disorders that narrow arteries and decrease blood inflow (such as atherosclerosis, diabetes, or a blood clot) or surgery on the blood vessels can cause erectile dysfunction. Also, abnormalities in the veins of the penis can sometimes drain blood back to the body so rapidly that erections cannot be sustained despite adequate blood inflow.
Neurologic damage is another possible cause of erectile dysfunction. Damage to the nerves leading to or from the penis produces erectile dysfunction. Such damage could result from surgery (most commonly prostate surgery), spinal disease, diabetes, multiple sclerosis, peripheral nerve disorders, stroke, alcohol, and drugs.
Occasionally, hormonal disturbances (such as abnormally low levels of testosterone) cause erectile dysfunction. Also, factors that decrease a man's energy level (such as illness, fatigue, and stress) can make erections difficult.
Many drugs can interfere with the ability to achieve an erection, especially among older men. Drugs that commonly cause erectile dysfunction include antihypertensives, antidepressants, some sedatives, cimetidine, digoxin, lithium, and antipsychotics.
Psychologic issues (such as depression, performance anxiety, guilt, fear of intimacy, and ambivalence about sexual orientation) can impair the ability to achieve erections. Psychologic causes are more common in younger men. Any new stressful situation, such as a change of sex partners or problems with relationships or at work, can also contribute.
Symptoms
Sex drive (libido) often decreases in men with erectile dysfunction, although some men do maintain a normal libido. Regardless of whether libido changes, men with erectile dysfunction have difficulty engaging in intercourse either because the erect penis is not sufficiently hard, long, or elevated for penetration or because the erection cannot be sustained. Some men stop having erections during sleep or upon awakening. Others may attain strong erections sometimes but be unable to attain or maintain erections other times.
When testosterone levels are low, the result is more likely to be a drop in libido than erectile dysfunction. Low testosterone levels can cause gradual development of many symptoms, including enlargement of the breasts (gynecomastia (see Section 21, Chapter 237)), raised pitch of the voice, shrinking of the testes (testicles), and loss of pubic hair. Low testosterone may also cause thinning of the bones, loss of energy, and loss of muscle mass.
Diagnosis
To diagnose erectile dysfunction, a doctor performs a general physical examination and examines the man's genitals. The doctor may also assess the function of the nerves and blood vessels that supply the genitals. Measurement of blood pressure in the legs may reveal a problem with the arteries in the pelvis and groin that supply blood to the penis. Examination of the man's rectum may reveal a problem with the nerve supply of the penis.
A blood sample is taken to measure the level of testosterone. Certain blood tests can help identify diseases that may lead to temporary or permanent erectile dysfunction. For example, blood tests can reveal evidence of diabetes (which can lead to permanent erectile dysfunction) or infection (which can lead to temporary erectile dysfunction).
If a problem with the arteries or veins is suspected, specialized tests may be performed. Ultrasound examination can reveal narrowing or blockage within the arteries of the penis.
Treatment
Some men and their partners may choose not to pursue treatment for erectile dysfunction. Physical contact without an erection may satisfy their needs for intimacy and fulfillment.
Sometimes, discontinuing use of a particular drug can improve erections.
For men who choose to pursue treatment, there are many choices.
Drug Treatment: Many drugs are used to treat erectile dysfunction. Most drugs given to treat erectile dysfunction increase blood flow to the penis. Most of these drugs are given by mouth, but some drugs can be applied locally--by injection or insertion into the penis.
Sildenafil is the drug most frequently used to treat erectile dysfunction. Sildenafil, which is taken by mouth, increases the frequency and rigidity of erections within 30 to 60 minutes; erections last about 10 to 30 minutes. The drug is effective only when the man is sexually aroused. Side effects of sildenafil include headache, flushing, runny nose, upset stomach, and vision problems. More serious side effects, including dangerously low blood pressure, can occur when sildenafil is taken with certain other drugs (such as nitroglycerin or amyl nitrite). Because of this, a man should not take sildenafil while taking drugs such as nitroglycerin. Drugs similar to sildenafil are likely to become available in the future.
Other oral drugs that have been used in the treatment of erectile dysfunction are phentolamine, yohimbine, and testosterone. Phentolamine is sometimes prescribed for erectile dysfunction but is less effective than sildenafil. Yohimbine is occasionally used to treat men whose erectile dysfunction is caused by psychologic factors, but the drug can cause side effects (including anxiety, shaking, rapid heart rate, and increased blood pressure) and is only minimally effective.
Drugs injected or inserted into the penis widen the arteries that supply blood to the penis. Men who cannot tolerate drugs taken by mouth can often be treated with these drugs.
Alprostadil, in the form of a pellet (suppository), can be inserted into the penis through the urethra. When used alone, alprostadil may result in an erection, but it is more effective when combined with another treatment, such as a binding device. Alprostadil may cause lightheadedness, a burning sensation of the penis, or, occasionally, a prolonged, painful erection (priapism (see Section 21, Chapter 238)). Because these serious side effects occasionally occur, a man usually takes his first dose under observation in a doctor's office.
A man can also induce an erection by injecting drugs (such as alprostadil alone or a combination of alprostadil, papaverine, and phentolamine) into the shaft of his penis. Injection is one of the most effective ways to obtain an erection. However, many men are unwilling to inject their penis. Also, the injection can cause priapism, and repeated injections may eventually produce scar tissue.
Testosterone replacement therapy may help men whose erectile dysfunction is caused by abnormally low testosterone levels. Unlike other drugs, which work by increasing blood flow to the penis, testosterone works by correcting a hormonal deficiency. Testosterone can be taken in many forms, including pills, patches, topical creams, and injections. Side effects can include liver dysfunction, increased red blood cell counts, increased risk of stroke, and enlargement of the prostate (see Section 21, Chapter 237).
Constriction (binding) and Vacuum Devices: Most men with erectile dysfunction can achieve erections by using a constriction device with or without a vacuum device. These devices are among the least expensive treatments for erectile dysfunction, and they enable a man to avoid the side effects that can occur with drug treatment. However, the devices can cause excessive bruising in men who are taking blood-thinning (anticoagulant) drugs and in those with diseases that interfere with blood clotting. Constriction devices should not be left on for longer than 30 minutes.
Constriction devices (such as bands and rings made of metal, rubber, or leather) are placed at the base of the penis to slow the outflow of blood. These medically engineered devices can be purchased with a doctor's prescription in a pharmacy, but inexpensive versions (often called "cock rings") can be purchased in stores that sell sexual paraphernalia.
A constriction device used alone may produce an erection in a man with mild erectile dysfunction, especially when the problem is maintenance of the erection. A constriction device can also be used in combination with a vacuum device. A binding device occasionally causes pain or interferes with ejaculation.
Vacuum devices (which consist of a hollow chamber attached to a source of suction) fit over the penis, creating a seal. Suction applied to the chamber draws blood into the penis, producing an erection. Once an erection is achieved, a binding device is applied to prevent the blood from flowing out of the penis.
Surgery: When erectile dysfunction does not respond to other treatments, a device that simulates an erection (prosthesis) can be surgically implanted in the penis.
A variety of prostheses are available. One type consists of firm rods that are inserted into the penis to create a permanently hard penis. Another prosthesis is an inflatable balloon that is inserted into the penis; before having intercourse, the man inflates the balloon with a small pump (which may be part of the prosthesis). Surgical implantation of a penile prosthesis requires at least a 3-day hospitalization and a 6-week recovery before intercourse is attempted.
Psychologic Therapy: Some types of psychologic therapy (which include behavior-modification techniques, such as the sensate focus technique (see Section 22, Chapter 250)) can improve the mental and emotional factors that contribute to erectile dysfunction. Psychologic therapy can even help when the erectile dysfunction has a physical cause, because psychologic factors often compound the problem.
Specific therapies are selected based on the particular psychologic cause of the man's erectile dysfunction. For example, if the man is suffering from depression, psychotherapy or antidepressants may help with erectile dysfunction. Sometimes psychotherapy can reduce anxiety about sexual performance in men with erectile dysfunction from any cause. Improvement may take a long time, and many sessions are usually required. A man, and often his partner, must be highly motivated for psychotherapy to work.
Several folk remedies for erectile dysfunction exist, but none have proven to be effective.
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