Impotence/Erectile Dysfunction

Erectile dysfunction (ED) or male impotence is defined as the inability of a man to achieve and maintain an erection sufficient for mutually satisfactory intercourse with his partner.

Sexual health and function are important determinants of quality of life. As Americans age, disorders such as erectile dysfunction (ED) or impotence are becoming increasingly more important. Because this subject is discussed widely in the media, men and women of all ages are seeking guidance in an effort to improve their relationships and experience satisfying sex lives.

Sexual dysfunction is often associated with disorders such as diabetes, high blood pressure, heart disease, nervous system disorders, and depression. Erectile dysfunction may also be an unwanted side effect from medication. In some men, sexual dysfunction may be the symptom of such disorders that brings them to the doctor's office.

The successful treatment of impotence has been demonstrated to improve intimacy and satisfaction, improve sexual aspects of quality of life as well as overall quality of life, and relieve symptoms of depression.

Premature ejaculation is often confused with erectile dysfunction. Premature ejaculation is a condition in which the entire process of arousal, erection, ejaculation, and climax occur very rapidly, often in just a few minutes or even seconds, leaving the partner unsatisfied. Premature ejaculation may accompany an erection problem such as ED but is generally treated differently.

Although this information focuses primarily on male ED, remember that the partner plays an integral role. If successful and effective management is to occur, any discussion of treatment should include the couple.

• For a man to have an erection, a complex process takes place within the body.
  
  
  • Erection involves the central nervous system, peripheral nervous system, psychological and stress-related factors, local problems with the erection bodies or penis itself as well as hormonal and vascular (blood flow or circulation) factors. The penile portion of the process leading to erections represents only a single component of a very complicated and complex process.
    
    
  • Erections occur in response to touch, smell, and visual stimuli that trigger pathways in the brain. Information travels from the brain to the nerve centers at the base of the spine, where primary nerve fibers connect to the penis and regulate blood flow during erection and afterward.
    
    
  • Sexual stimulation causes the release of chemicals from the nerve endings in the penis that trigger a series of events that ultimately cause muscle relaxation in the erection bodies of the penis. The smooth muscle in the erection bodies controls the flow of blood into the penis. When the smooth muscle relaxes, the blood flow dramatically increases, and the erection bodies become full and rigid, resulting in an erection. Venous drainage channels are compressed and close off as the erection bodies enlarge.
    
    
  • Detumescence (when the penis is no longer in a state of erection) results when muscle-relaxing chemicals are no longer released. Ejaculation causes the smooth muscle tissue of the erection bodies in the penis to regain muscle tone, which allows the venous drainage channels to open and the blood drains from the penis.
    
    
• Sexual dysfunction is extremely common in men.
  
  
  • In the Massachusetts Male Aging Study (MMAS) among a community-based survey of men aged 40-70 years, 52% of the men reported some degree of erectile difficulty. Complete ED, defined as the total inability to obtain or maintain suitable erections during sexual stimulation, as well as the absence of nocturnal erections (erections during sleep), occurred in 10% of the men in the study. Lesser degrees of mild and moderate ED occurred in 17% and 25% of participants.
    
    
  • In the National Health and Social Life Survey (NHSLS), a nationally representative sample of men and women aged 18-59 years, 10.4% of men reported being unable to achieve or maintain an erection during the past year.
    
    
  • Judging from research results, an estimated 18-30 million men are affected by ED.
    
    
  • Other male problems, such as premature ejaculation and loss of libido (decreased sexual desire), are also very common. The NHSLS found that 28.5% of men aged 18-59 years 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.

Erectile dysfunction can be caused by any number of physical and psychological factors. In general, ED is divided into organic (having to do with a bodily organ or organ system) and psychogenic (mental) impotence, but most men with organic causes have a mental or psychological component as well.

Erection problems will usually produce a significant psychological and emotional reaction in most men. This is often described as a pattern of anxiety and stress that can further interfere with normal sexual function. This "performance anxiety" needs to be recognized and addressed by your doctor.

• Almost any disease can affect erectile function by altering the nervous, vascular, or hormonal systems. Various diseases may produce changes in the smooth muscle tissue of the penis or influence mood and behavior.

• Vascular diseases account for nearly half of all cases of ED in men older than 50 years. Vascular disease includes atherosclerosis (fatty deposits on the walls of arteries, also called hardening of the arteries), a history of heart attacks, peripheral vascular disease (problems with blood circulation), and high blood pressure. Prolonged tobacco use (smoking) is considered an important risk factor for ED because it is associated with poor circulation and reduced blood flow in the penis.

• 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).

• Medications used to treat other medical disorders may cause ED.

• Systemic diseases associated with ED
  • Diabetes

  • Scleroderma

  • Renal (kidney) failure

  • Liver cirrhosis

  • Hemachromatosis (too much iron in the blood)

  • Cancer and cancer treatment

• Diseases of the nervous system associated with ED
  • Epilepsy

  • Stroke

  • Multiple sclerosis

  • Guillain-Barré syndrome

  • Alzheimer disease

  • Trauma

  • Parkinson disease

• Respiratory disease associated with ED: Chronic obstructive pulmonary disease

• Endocrine conditions associated with ED
  • Hyperthyroidism

  • Hypothyroidism

  • Hypogonadism

• Penile conditions associated with ED
  • Peyronie disease

  • Priapism (painful, abnormally prolonged erections)

• Mental conditions associated with ED
  • Depression

  • Widower syndrome

  • Performance anxiety

• Nutritional states associated with ED
  • Malnutrition

  • Zinc deficiency

• Blood diseases associated with ED
  • Sickle cell anemia

  • Leukemias

• Surgical procedures associated with ED
  • Procedures on the brain and spinal cord

  • Retroperitoneal or pelvic lymph node dissection

  • Aortoiliac or aortofemoral bypass

  • Abdominal perineal resection

  • Proctocolectomy

  • Radical prostatectomy

  • Transurethral resection of the prostate

  • Cryosurgery of the prostate

  • Cystectomy

• Common medications associated with ED
  • Antidepressants

  • Antipsychotics

  • Antihypertensives (for high blood pressure)

  • Antiulcer drugs such as cimetidine (Tagamet)

  • Hormonal medication such as Zoladex, Lupron, finasteride (Proscar), or dutasteride (Avodart)

  • Drugs that lower cholesterol

  • Alcohol abuse

  • Mind-altering agents such as marijuana and cocaine

Schedule enough time with your doctor to conduct a full interview and physical examination. The first step in the medical management of erectile dysfunction is taking a thorough sexual, medical, and psychosocial history. Erectile dysfunction is a delicate topic, and your doctor should be sensitive and caring to make you comfortable about sharing these intimate details of your private life.

• Your doctor will ask if you have difficulty obtaining an erection, if the erection is suitable for penetration, if the erection can be maintained until the partner has achieved orgasm, if ejaculation occurs, and if both partners have satisfaction.
  
  
• You will be asked about current medications you are taking, about any surgery you may have had, and about other disorders (history of trauma, prior prostate surgery, or radiation therapy, for example).
  
  
• The doctor will want to know all medications you have taken during the past year, including all vitamins and other dietary supplements.
  
  
• Tell the doctor about your tobacco use, alcohol intake, and caffeine intake, as well as any illicit drug use.
  
  
• Your doctor will be looking for indications of depression. You will be asked about libido (sexual desire), problems and tension in your sexual relationship, insomnia, lethargy, moodiness, nervousness, anxiety, and unusual stress from work or at home.
  
  
• You will be asked about your relationship with your partner. Does your partner know you are seeking help for this problem? If so, does your partner approve? Is this a major issue between you? Is your partner willing to participate with you in the treatment process?
  
  
• Your doctor will want your candid answers to questions like these:
  
  
  • How long has a problem existed? Did a specific event such as a major surgery or a divorce occur at the same time?
    
    
  • Do you have diminished sexual desire? If so, do you think it is just a reaction to poor performance?
    
    
  • How hard or rigid are your erections now? Are you ever able to obtain an erection suitable for penetration even momentarily? Is maintaining the erection a problem?
    
    
  • Can you achieve orgasm, climax, and ejaculation? If so, does it feel normal to you? Does the penis become somewhat rigid at climax?
    
    
  • Do you still have morning erections?
    
    
  • Is penile curvature (Peyronie disease) a problem?
    
    
  • What would be your preferred frequency of intercourse, assuming the erections were working normally? How would your partner answer this same question? What was your frequency before the erections became a problem?
    
    
  • Have you already tried any treatments for ED yet? If so, what were they and how did they work for you? Were there any problems or side effects to their use?
    
    
  • Are you interested in trying a particular treatment first? Are you against trying a particular type of therapy? If so, what caused you to make this judgment?
    
    
  • To what degree do you wish to proceed in determining the cause of your ED? How important is this information to you?
    
    
• A physical examination is necessary. The doctor will pay particular attention to the genitals and nervous, vascular, and urinary systems. Your blood pressure will be checked because several studies have demonstrated a connection between high blood pressure and erectile dysfunction. The physical examination will confirm information you gave the doctor in your medical history and may help reveal unsuspected disorders such as diabetes, vascular disease, penile plaques (scar tissue or firm lumps under the skin of the penis), testicular problems, low male hormone production, injury, or disease to the nerves of the penis and various prostate disorders.

• Laboratory testing: Laboratory testing is necessary for most men, although no laboratory work may be needed.
  
  
  • If laboratory tests are performed, they would normally start with an evaluation of your hormone status (testosterone or male hormone), particularly if one of your symptoms is low sexual desire (low libido). Blood tests for testosterone should ideally be taken early in the morning because that's when levels are usually at their highest. Other blood tests, such a luteinizing hormone and prolactin, can help determine if there is a problem with the pituitary gland.
    
    
  • Your blood may be checked for glucose, cholesterol, thyroid function, triglycerides, and prostate-specific antigen (PSA).
    
    
  • A urinalysis looking for blood cells, protein, and glucose (sugar) may also be done.
    
    
• Imaging: An ultrasound may be performed. This test may be done on the lower abdomen, pelvis, and testicles, or restricted to just the penis.
  
  
  • A duplex ultrasound is a diagnostic technique that uses painless, high frequency sound waves to visualize structures beneath the skin's surface. The principle is similar to the sonar used on submarines. Sound waves are reflected back when they contact relatively dense structures such as fibrous tissue or blood vessel walls. These reflected sound waves can be converted into pictures of the internal structures being studied.
    
    
  • This procedure is usually performed before and after injection of a smooth muscle relaxing medication into the penis, which normally should significantly increase the diameter of the penile arteries. The procedure itself is painless. Duplex ultrasonography is most useful in evaluating possible penile arterial disorders, but further studies of the venous drainage system as well as arterial x-rays are usually recommended if vascular reconstructive surgery is anticipated.
• 
  
• Further testing: Following completion of this phase, the doctor should be able to determine the general type of dysfunction and the need for additional testing such as penile or pelvic blood flow studies, nocturnal penile tumescence testing, penile biothesiometry (nerve testing), or additional blood tests. Your doctor will discuss your results with you (including your partner when possible), summarize the risk factors such as smoking and medications that may be involved, review the various treatment options that can be considered, and work with you to develop a strategy and program to help you and your partner achieve a satisfactory result.
  
  
  • One of the most common tests used to evaluate penile function is the direct injection of PGE1 into the penis. (PGE1 is a medication that increases blood flow into the penis and normally produces erections.) If the penile structure is normal or at least adequate, an erection should develop within several minutes. You and your doctor can judge the quality of the erection. If successful, this test also establishes penile injections as one possible therapy.
    
    
  • 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 2 or 3 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.
    
    
  • Formal neurological testing is not needed for most men. But anyone with a history of nervous system problems such as loss of sensation in the arms or legs and those with a history of diabetes may be asked to undergo testing.
    
    
  • The sensitivity of the skin of the penis to detect vibrations (biothesiometry) can be used as a simple office nerve function screening test. This involves the use of a small vibrating test probe placed on the right and left side of the penile shaft as well as on the head of the penis. The strength of the vibrations is increased until you can feel the probe vibrating clearly. Although this test does not directly measure the erectile nerves, it serves as a reasonable screening for possible sensory loss and is simple to perform. More formal nerve conduction studies are only performed in selected cases.

Currently, virtually any man who wishes to have erectile function can obtain it, regardless of the underlying cause of his problem. Many reasonable treatment options exist. Your first step is to find a well-trained, experienced, and compassionate doctor who is willing to take the time to understand you and fully discuss the treatments available to you.

Sex counseling is an important part of erectile dysfunction management. Many professional sex counselors are skilled in working with patients with ED, but your primary care doctor and urologist may also serve in this capacity to some degree. These are usually the first professionals to learn about the problem. Men are frequently reluctant to discuss their sexual problems and need to be specifically asked. Opening a dialogue allows your doctor to begin the investigation or refer you to a consultant. After testing is completed, your doctor can then discuss your particular situation, the most likely cause, and reasonable treatment options.

Options include sex counseling, medications, external vacuum devices, hormonal therapy, penile injections or intraurethral suppositories. In highly selected cases under the supervision of a urology specialist in ED, combination therapy using several of these methods together can be used. If none of these therapies is satisfactory, penile prosthesis implants can be considered.

• Vacuum devices: Specially designed vacuum devices to produce erections have been used successfully for many years. They are safe and relatively inexpensive. They work by using a manually generated vacuum to draw blood into the penis to create the erection. When used successfully, their other significant benefit is a high degree of reliability compared to drug treatments, which tend to be less predictable. The typical vacuum device consists of a plastic cylinder that is placed over the penis, tension rings of various sizes, and a small hand pump. Air is pumped out, causing a partial vacuum, which creates the erection. Once an erection is obtained, a tension ring, which acts like a tourniquet to keep the blood in the penis and maintain an erection, is placed at the base of the penis. This technique is effective in 60-90% of men. It is not recommended to leave the tension ring in place longer than 30 minutes.
  
  
  • These devices are generally safe, but bruising can occur. Other unwanted effects include pain, lower penile temperature, numbness, no or painful ejaculation, and pulling of scrotal tissue into the cylinder. Many of these problems can be helped by proper selection of the tension rings and cylinder, use of adequate lubrication, and proper technique.
    
    
  • The devices are very reliable and seem to work better with increased use and practice. They can be operated and used quickly with experience but still are perceived to be less romantic than other options.
    
    
  • One drawback to the use of these external vacuum devices is the need to assemble the equipment and the difficulty in transporting it. Many men lose interest in using the device because of the preparations that are necessary, lack of easy transportability, inability to hide the tension ring, and the relative lack of spontaneity.
    
    
  • About half the men who use a vacuum device obtain good or excellent erections with them, but only half of these men consistently use the device over long periods of time.
  
  
• Sildenafil citrate (Viagra): Viagra is a prescription medication for the treatment of erectile dysfunction. It's the first oral medicine (a pill you take by mouth) available that's been proven to improve erections in most men with impotence. Since its introduction in March 1998, no other therapy for ED has achieved such wide public recognition. Viagra doesn't improve erections in normal men, only in those with difficulty in achieving or maintaining erections sufficient for sexual intercourse due to a true medical problem. It is not an aphrodisiac and will not increase desire. Unlike other treatments for erectile dysfunction, Viagra requires sexual stimulation to function. Without this stimulation, Viagra won't have any effect.
  
  
  • Viagra works by blocking an enzyme found mainly in the penis that breaks down a chemical produced during stimulation that normally produces erections. Viagra allows this chemical of arousal to survive longer and improves erection function. That is also why sexual stimulation is necessary for Viagra to work.
    
    
  • In general, Viagra works successfully in about 65-70% of all impotent men. The greater the degree of damage to the normal erection mechanism, the lower the overall success rate. Men with diabetes and those with spinal cord injury reported between 50-60% responding successfully to treatment with Viagra. The worst response rate was in men who became impotent after radical prostate cancer surgery. But even in this hard-to-treat group, 43% reported improved erections particularly if they had the "nerve-sparing" type of prostate surgery.
    
    
  • Viagra works best if taken about 1 hour before sexual activity. Only 1 tablet should be taken per day. It should be taken on an empty stomach. Increasing the dosage of Viagra beyond the recommended amounts will not improve the response and will only result in greater side effects.
    
    
    • The most common side effect of Viagra use is headache, affecting about 16% of users. A drop in blood pressure, transient dizziness, and facial flushing are reported in 10%. Indigestion occurs in 7%, and nasal congestion in 4%.
      
      
    • Between 3% and 11% of users report some visual problems while on Viagra. This visual disturbance is described as either blurred vision, increased light sensitivity, persistence of a bluish tinge or temporary loss of the ability to distinguish between blue and green.
      
      
    • None of these side effects is severe and most are described as mild. Very few users stop taking the medication because of side effects.
    
    
  • Viagra is absolutely not to be taken by men with heart conditions who are taking nitrates such as nitroglycerine or isosorbide (Isordil, Ismo, Imdur). Those with serious heart disease, exertional angina (chest pain), and those taking multiple drugs for high blood pressure are advised to seek the advice of a heart specialist before beginning therapy with sildenafil.
    
    
  • No nitrate-based drugs should be given to men with suspected heart attacks if they have taken Viagra within 24 hours. Combining Viagra with nitrate-based medications can cause a severe and dramatic drop in blood pressure with potentially very dangerous consequences. This is also why you should absolutely never share your Viagra prescription with anyone else. If they happen to be taking one of the drugs that interacts dangerously with Viagra, the results could be very serious. If there is any question about possible drug interactions, always check with your doctor or pharmacist.
    
    
  • Certain street drugs such as "poppers" also can cause serious problems if taken with Viagra. Ecstasy is a street drug that may increase sexual desire but interferes with performance. This has prompted some men to combine ecstasy with Viagra. This mixture (a combination sometimes called "sextasy") can improve erection ability but also causes severe headache and priapism. (Priapism is an abnormally prolonged erection that becomes extremely painful and may result in permanent damage to the erection mechanism.) There are also potentially dangerous effects to your heart from mixing Viagra with various other street drugs.
    
    
  • Several medications can interfere with the chemical processing of Viagra by the liver. These can include ketoconazole (an antifungal medication known by the brand name Nizoral), erythromycin (an antibiotic), and cimetidine (also known as Tagamet, for reducing stomach acid). A lower dose of Viagra should be used if you are taking any of these medications.
    
    
  • Sildenafil is available in 3 doses: 25 mg, 50 mg, and 100 mg. The starting dose depends on the clinical situation. A man in his 50s with mild sexual dysfunction that is probably related to psychological factors can start on the 25 mg dose. Men with moderate-to-severe ED can begin at the 50 mg dose, and, after testing the effect of the drug on at least 3 occasions, the dose can be modified. Men with severe ED may need to quickly move up to the 100 mg dose. These men are less likely to achieve a satisfactory response, but they should make at least 3-4 attempts with the drug before considering another form of therapy.
    
    
  • Sildenafil should be taken on an empty stomach about 45-60 minutes prior to sexual intercourse. Stimulation is necessary to produce an erection. An increased ability to achieve good erections can last up to 24 hours but usually only about 4 hours. The drug should not be taken daily.
    
    
  • Several drugs very similar to Viagra have recently been approved by the FDA.  These drugs, called vardenafil (Levitra) and tadalafil (Cialis), have essentially the same activity and general precautions as Viagra. Cialis has a longer duration of increased sensitivity to develop an erection (up to 24-36 hours) compared with Viagra and Levitra (up to 4 hours).

• Yohimbine: This herbal product has been available for many years. It comes from the bark of a West African tree. Its use has been questioned because, even in good, well-controlled studies, yohimbine is only slightly better than placebo (no drug at all). A renewed interest in this agent has occurred, particularly when combined with sildenafil or some of the other oral drugs. Yohimbine is safe with few known adverse effects. The customary daily dose is one tablet of 5.4 mg taken 3 times a day.
  
  
• Apomorphine (Uprima): Apomorphine is a medication that dissolves under your tongue. It is not yet approved by the Food and Drug Administration (FDA). Apomorphine has a central effect on the hypothalamus, which is an area in the brain known to involve erections. Side effects are nausea, sweating, dizziness, drowsiness, vomiting, yawning, and weakness. Most of these were considered mild to moderate.
  
  
• Testosterone: Men with low sex drive and ED may be found to have low testosterone levels. Hormone replacement may be of benefit by itself or as a complementary therapy used with other treatments. Libido and an overall sense of well-being are likely to improve when serum testosterone levels are restored.
  
  
  • Replacement testosterone is available as pills, injections, patches, and a gel that is rubbed into the skin. Men with low sexual desire and ED may have low testosterone (male hormone) levels. Hormone replacement may occasionally be of some benefit, especially when used in combination with other therapies. Testosterone supplementation alone is not particularly effective in treating erectile dysfunction. Sexual desire and an overall sense of well-being are likely to improve when serum testosterone levels (the levels in the blood) are restored.
    
    
  • As a general guideline, testosterone levels of 300 or less is considered low, but this varies depending on the laboratory that does the testing.
    
    
  • Oral therapy (pills) is the least effective and the most likely to be associated with liver problems, even though this is a small risk. Injections are most likely to restore testosterone levels, but this therapy requires periodic injections, usually every 2 weeks, to sustain an effective level. Skin patches and gels deliver a sustained dose and generally are well accepted.
    
    
  • Follow-up testosterone (hormone) levels and periodic blood counts and prostate checks are necessary for all men on long-term testosterone replacement therapy.
  
  
• Injection therapy: Although many substances are touted as aphrodisiacs (meant to arouse sexual desire), the modern age of such drug therapies began in 1993 when the injection of papaverine, an alpha blocker that produces vasodilatation (widening of the blood vessels), was shown to produce erections when injected directly into the penis. Soon afterward, other vasodilators, such as PGE1 and Regitine, were demonstrated to be effective either as single drugs or in combination.
  
  
  • Self-injection of these agents has been of enormous benefit because they represent the most effective way to achieve erections in a wide variety of men who otherwise would be unable to achieve adequate rigid erections.
    
    
  • If the structure of the penis is healthy, the use of injectable drugs is almost always effective. If you choose this therapy, your doctor will teach you how to perform the injections, and the urologist (specialist) must determine the appropriate dose. The dosage is adjusted to achieve an erection with adequate rigidity for no more than 90 minutes.
    
    
  • Alprostadil, a synthetic PGE1, is the most commonly used single drug for injections into the penis as a treatment for ED. It works well in the majority of men who try it. In one study of 683 men with ED, 94% reported having erections suitable for penetration after alprostadil (PGE1) injections. When PGE1 is used in combination with papaverine and Regitine, the mixture is called Trimix, which has roughly twice the effectiveness of alprostadil alone. However, Trimix is quite expensive and is usually not covered by insurance, while PGE1 is often a covered benefit in most insurance medication plans. The main side effects are pain from the medication (not from the injection), priapism (persistent or abnormally prolonged erection), and scarring at the site of the injection. Many men are uncomfortable with penile injection therapy even though the injection itself is painless. The injection cannot be done more often than 3 times a week. Men on anticoagulant medications (blood thinners) should probably choose an alternate therapy.
  
  
• Intraurethral therapy (Medicated Urethral System for Erections, MUSE): Alprostadil, PGE1, has been formulated into a small suppository that can be inserted into the urethra (the canal through which urine and semen are excreted). In a selected group of men, the drug was effective in 65%. This drug may be effective in men with vascular disease, diabetes, and following prostate surgery. This is a useful alternative for men who do not want to use self-injections or for men in whom oral medications have failed. It has been quite successful when used together with sildenafil (Viagra) in cases where each drug alone has failed. This type of combination treatment should ONLY be done under the supervision of a urologist experienced in ED. Few side effects occur. The most common is pain at the site where the pellet is deposited. There may also be a small amount of bleeding. It is important for the user to urinate immediately before using the MUSE system. A temporary tourniquet is often helpful in allowing the medication to stay in the erectile tissue a little longer and seems to give a somewhat better response.
  
  

Types of Medical Therapy Available to Manage Erectile Dysfunction