What is impotence?
While the word has many meanings (literally, a “lack of power”), the term has been used in the medical literature to denote a man’s inability to obtain or sustain an erection sufficient for satisfying sex. More recently, clinical researchers have begun to use the more precise term erectile dysfunction (ED).
ED can be a chronic sexual health problem, but it’s important to put it in context. Virtually all men experience erectile dysfunction at one time or another. Anxiety, fatigue, or too much alcohol are common causes. If a man does experience isolated episodes of erectile dysfunction, it’s unwise for him to spend time worrying about the problem because this can create a psychological barrier to arousal. Remember: Such episodes are normal; they are generally not harbingers of any chronic problem.
Estimates of the number of American men with chronic ED range from roughly 10 million to 18 million. Studies show that half of men over age 40 have at least intermittent problems with ED.
What are the leading causes of ED?
The causes of ED break down broadly into three categories: psychological problems, medical conditions, and the adverse effects of medication. It was formerly thought that erectile dysfunction was mainly a psychological issue, but more recent data show that the problem is usually physical. In fact, in one Veterans Administration study, only 14% of ED cases had psychological causes. Impotence can be a sign or a symptom of a more serious medical condition, so if you’re having a chronic problem with ED, it’s best to consult a medical professional to get the proper evaluation and treatment.
What medical conditions cause ED?
Some of the major culprits are diseases that affect the vascular system. As we discussed earlier, increased blood flow to the penis is the mechanism for erection, and an ailment that impedes this process will have a direct result on erectile capacity. Heart disease, high blood pressure, and hardening of the arteries are implicated in ED. Men with heart disease or high blood pressure who also smoke have an increased risk. Diabetes is another frequent factor in ED. This, too, stems from the ill effects of diabetes on blood circulation.
Hormonal problems are another important cause. Each day, men secrete quantities of the hormone testosterone, which plays a major role in sexual function. A shortage of this hormone can lead to a loss of interest in sex, ED, and a longer list of health problems. We will talk about all aspects of testosterone deficiency later.
Other causes of ED include thyroid problems (slow metabolism also slows sexual response); alcoholism; abuse of illegal drugs; spinal cord and other nerve injuries; and of bladder or kidney problems.
What types of medications contribute to erectile problems?
Erectile problems–often temporary, it should be noted–are a possible side effect of several classes of drug, the following examples among them:
- Diuretics – bendroflumethiazide (Naturetin), chlorothiazide (Diuril), spirinolactone (Aldactone)
- Antihypertensives – propranolol (Inderal), clonidine (Catapres), methyldopa (Aldomet), guanethidine (Isemelin), and Reserpine (Diupres)
- Antidepressants – clomipramine (Anafranil) and phenelzine (Nardil)
- Antipsychotics – lithium (Eskalith), fluphenazine (Prolixin), and thioridazine (Mellaril)
The list also includes most types of steroids and most antiepileptic drugs. If you have questions about adverse sexual effects of a medication you’re taking, ask your healthcare provider or pharmacist for details from the product’s package insert, which summarizes the research data.
What psychological factors can cause ED?
The leading psychological cause of ED is probably anxiety about performing well sexually. If a man is worried about having or maintaining an erection, he can sometimes fixate on the status of his genitals, and this can short-circuit his sexual arousal. More generalized stress also can interfere with erections, as can depression. In some cases, there is a fine line between ED per se and more general problems of diminished sexual drive. Depression, which is common among the elderly, may cause loss of desire, but medications used to treat depression can also impair sexual function.
How can the physical and psychological causes of ED be distinguished?
Several tests can be used to sort out physical from psychological causes. The most simple is a blood test to see if testosterone levels are within the normal range. Other procedures include the following:
- Nocturnal penile tumescence (NPT) – As strange as it may sound, one of the most effective diagnostic tools is to observe the pattern of a man’s erections during sleep. Lab technicians attach a painless monitoring device to the penis and then record the frequency and duration of erections during certain phases of sleep. NPT is usually done in a clinical. It’s not a perfect test, in part because it assumes healthy sleep patterns, even though many people suffer from sleep disturbances. All the same, if the man being monitored produces firm erections when sleeping, the causes of an erectile problem are less likely to be physical than psychological.
- Measurement of penile firmness by means of a snap gauge or stamp test – Both methods measure nocturnal erections, albeit less scientifically than NPT. The snap gauge is a plastic ring that straps around the penis and is thin enough to break if a full erection occurs. In a homemade version, some people ring the penis with a sealed strip of postage stamps, which, if broken, may show evidence of erections during sleep. The problem with both of these methods is that the gauges may be broken by normal sleep movement. Plus, neither records the number or duration of erections.
- Injections – Injections of drugs such as prostaglandin or papaverine will reliably produce erections in men with proper vascular function and offer a good way to confirm that blood supply to the penis is adequate.
Other tests attempt to track blood flow in the penis with ultrasound or x-rays after the injection of a special dye. While each of these tests has its place, answers are sometimes difficult to come by. ED may have complex causes, perhaps involving both the side effects of medication and resulting performance anxiety.
How is ED treated?
Up until 1998, only an estimated 10% of men with ED actually sought treatment, but that has changed dramatically with the advent of sildenafil (Viagra). Sildenafil has become one of the fastest-selling prescription drugs of all time since its launch in early 1998. Other treatments, however, can also be quite effective. These include a suppository that is placed in the urethra, penile injection, vacuum pumps, vascular surgery, and various prostheses (although most experts agree that prostheses should be viewed as a last resort). The drug yohimbine, extracted from an African tree bark, is also available in both over-the-counter and prescription strengths for treatment of ED, though it has been less well studied.
How does Viagra work?
The centers of action are the corpora cavernosa (CC) – two columns of erectile tissue running lengthwise down the center of the penis, on either side of the urethra. When a man becomes sexually aroused, a series of biochemical events leads to an increase in the concentration of a compound called cyclic guanosine monophosphate (cGMP) in the CC. The role of cGMP is to relax the smooth-muscle walls of the CC, allowing them to stretch and overfill with blood. “Inflation” of the CC with blood is what causes the penis to become stiff and rigid. Being able to obtain and maintain an erection is a good thing (most men would agree), but eventually, you want it to subside. That’s where another biochemical, an enzyme called phosphodiesterase type 5 (PDE5), comes into play. PDE5 is always present in the CC, and it’s job is to degrade cGMP, thus ending the smooth-muscle relaxation that made erection possible in the first place. What Viagra does is inhibit the action of PDE5, making it easier to achieve high levels of cGMP, which produces greater than usual smooth muscle relaxation, and greater than usual inflow of blood to the CC.
The enlargement of the corpora cavernosa during the course of an erection compresses veins in surrounding tissues, which reduces venous outflow and makes the engorged organ rigid.
How effective is Viagra?
In clinical studies involving thousands of volunteers with erectile dysfunction (ED) due to a number different causes, Viagra was effective in about 70% of men. ‘Effective’ in this case means the men were able to achieve and maintain an erection sufficient for the successful completion of penetrating vaginal intercourse. It’s important to define what we mean by ‘effective’ here because a lot of people have the mistaken impression that Viagra can restore sex drive or prevent premature ejaculation or “cure” any number of other sexual dysfunctions. Viagra can only help a man with ED achieve and maintain an erection in the presence of sexual stimulation.
Weren’t there some deaths among early users of Viagra? Is it safe?
There have been deaths among men using Viagra, but the question is: did Viagra cause any deaths? It appears not.
In the first 8 months Viagra was on the market (late March to mid-November 1998), 130 deaths were reported among users, worldwide. Bearing in mind that Viagra users tend to be older men, who are by virtue of their age more likely to have heart problems and other conditions and illnesses (for which many are also taking prescription medications), let’s have a quick look at the US Food & Drug Administration (FDA) analysis of the above-mentioned 130 deaths: 77 died from a cardiovascular event, (e.g., a heart attack); 3 died of stroke; 1 drowned; 1 was murdered; and for the remaining 48, the cause of death was not mentioned or known. No death was attributed directly to Viagra.
The major caveat – from the FDA and Pfizer (the manufacturer of Viagra) – is that Viagra is potentially dangerous in men taking nitroglycerin and other organic nitrates used for heart conditions. Viagra can potentiate the action of these drugs, resulting in sudden and potentially fatal loss of blood pressure. Sixteen of the 130 deaths among early Viagra users occurred among men who were also taking nitrates.
Viagra also interacts with several others drugs in such a way that Viagra dose should be reduced when those other drugs are “on board.” And there are other patients for whom Viagra is not appropriate. The probable safety of Viagra for any given patient depends on that patient’s health and other medications. No one should use Viagra without first undergoing a medical work-up to determine if any of the known contraindications (reasons not to use Viagra) apply.
Will health insurance and managed care plans pay for it?
Some do. Some don’t. Some restrictions may apply. You’ll need to check with individual plans for the most up-to-date information.
Urethral suppository (MUSE)
How does the urethral suppository work? What’s it like?
The urethral suppository system (MUSE), employs a pellet containing prostaglandin E1 (a.k.a., alprostadil) that is inserted through a push-button applicator into the urethra at the tip of the penis. The drug is absorbed directly through the lining of the urethra. This usually results in a firm erection in 5 to 10 minutes. MUSE-induced erections last 30 to 60 minutes, at an estimated per-dose cost of $18.
The apparatus is not elaborate and works well, but many men find inserting the pellets painful, and the process can cause irritation of the penis. This method also has the disadvantage that couples sometimes have to interrupt lovemaking for the medication. MUSE therapy for ED is reimbursable by some but not all health insurance plans.
How effective is the MUSE system?
In clinical studies, MUSE was effective in restoring functional erectile capability in about 50% of men.
What’s involved in penile injection therapy besides needles?
Penile injection, which uses a very fine gauge needle, is reportedly not nearly as painful as it might sound. In fact, most reports of pain with this drug center on the workings of the drug itself. Injection involves combinations of several drugs–among them alprostadil, the active ingredient of the MUSE suppository system (see above). Alprostadil dilates arteries inside the penis to create and prolong erection. Fifteen to 30 minutes after the injection, most men will have a firm erection that will last about an hour, at an estimated per-dose cost of $18.
Penile injection of alprostadil reliably produces erections that feel normal. But the necessity of using a needle is a major barrier for many men. There is also a chance the drug will produce local irritation. In a small number of cases, it may also result in priapism (a prolonged and sometimes painful erection), which can cause serious damage if not treated quickly. As with Viagra, the therapy is reimbursable by some but not all health insurance plans.
How does the vacuum pump work? What are its relative merits?
A man places a hollow cylinder over the shaft of his penis and draws out air with a hand pump; the resulting vacuum moves blood into the penis. After the cylinder is removed, a tension ring (essentially, a rubber band) is placed around the base of the penis to restrict the outflow of blood.
A one-time investment of $150 to $500, vacuum pumps may be a less expensive long-term option than prescription drugs such as Viagra, but they do have serious drawbacks. For one, they interrupt lovemaking. Also, the erection produced by a pump is not as rigid as one produced naturally or by some of the methods described above. Finally, pumps may cause irritation of the urethra or abrasion or damage to the penis if the ring at the base of the penis is left in place for more than 30 minutes.
How do penile implants work? Are the erections created by implants different from natural erections?
Penile implants come in two varieties: hydraulic and nonhydraulic. Hydraulic implants are hollow cylinders that can be inflated with a tiny mechanical pumping device that is inserted along with them. Activating these implants sometimes involves manipulating a pump in the scrotum or manipulating the head of the penis to begin the inflation process. The same pump is used to deflate the implants.
The nonhydraulic type consists of a pair of silicone implants that run lengthwise along the shaft of the penis, adding length and heft to the penis even in its flaccid state–in essence a permanent erection, but one that is malleable and can be concealed under clothing.
Erections produced by either implant are not as wide or as long as a natural erection, but they are adequate for vaginal intercourse and are available on demand. The big drawback with inserts is that they are not reversible. They also change the structure of the penis in ways that render ineffective some of the methods we listed before. Additionally, a problem such as malfunction of the pumping device will require further surgery, which can cost several thousand dollars. For these reasons, implants are generally considered methods of last resort.
Is yohimbine a real drug or a bit of folklore?
Yohimbine (Yocon, Yohimex, and others) is a real drug, sold by prescription and over the counter. It is presumed to work by increasing the arterial inflow of blood to the penis and decreasing venous outflow. It has a reputation as a complementary medicine, but it has been studied scientifically and is approved for the treatment of ED and delayed orgasm. Yohimbine does have some potentially adverse side effects, such as irritability, anxiety, and an increase in heart rate and blood pressure. Given the emergence of several other effective therapies in recent years, experts predict the use of Yohimbine will probably decrease.
How does aging affect erections?
Even in the absence of illness, men undergo a host of physiological changes that alter their sexual appetites and performance – everything from changes in blood flow and hormone levels to the way the nervous system responds to stimuli. A well-documented by-product of this natural aging process is that men require more direct stimulation to get an erection as they get older, and erections tend to become less firm. But these same factors that slow erections may also make it possible for older men to have intercourse for longer periods of time before reaching climax.
This change in the nature of erections occurs gradually over time, and it generally does not mean that men cannot have erections firm enough for intercourse. Therapists are quick to point out that even a decline in the number of erections doesn’t preclude having sex in the broadest sense, since older couples are more likely to engage in touching and caressing and to see these types of contact as an important part of their sexual relationships.