Erectile Dysfunction
Excerpted from "The Male Biological Clock" by Harry Fisch
Chapter 3: The Viagra Generation

Norm had a great life: wife, two kids, dog, nice home in a small town, and satisfying work. The only thing he didn’t have, it seemed, was sex.

Like many couples, Norm’s sex life with his wife Margaret had evolved from the passion-filled, playful, and lusty days of courtship, to the regular and satisfying sex of early marriage, through long sex-less stretches in the aftermath of children. Now, as he was approaching 50, sex was so infrequent he usually couldn’t remember the last time he and his wife made love.

Age and the sheer familiarity of sex with his wife played a role in Norm’s situation, but he also suspected another cause: his unpredictability as a lover.

Even in the early days of his marriage, Norm would occasionally lose his erection, usually during foreplay as he was helping his wife get aroused and lubricated. Often, by the time she was ready, he was limp.

“It’s just awful to have my wife lying there, ready and willing, and not be able to get an erection,” he says. “She said she understood, but I’m not sure she did and she was probably as frustrated by it as I was.”

The problem would come and go. Sometimes (often after he’d had a drink or two) he wouldn’t worry about his erection and sex would be, if not wild, at least mutually satisfying. But equally often, it seemed, his fear of losing his erection made it impossible to achieve one. Over the years, he initiated sex less and less often—and with the addition of children the excuses for doing so were easy to find.

“When you have kids you’re often both so exhausted that it’s really just easier not to have sex,” Norm says. “The thing is, I really wanted to have sex. Hell, when I masturbated I had no problems with erections then. But when it came to sex with Maggie…I just wasn’t confident. I’m sure she felt that, and I’m also sure it’s not exactly attractive.”

When Viagra became available, Norm didn’t consider trying it. He figured he wouldn’t be a candidate since he could, after all, get erections on his own. He didn’t see himself as having erectile dysfunction even though his history suggested a less-than-robust erectile capacity. But one day a fight with Maggie over who did more housework escalated and suddenly veered into her dissatisfaction with their sex life.

“She said, at one point, ‘I’m just not attracted to you sometimes, and the fact that you can’t make love to me doesn’t help.’ That’s when I decided to give the pill a try. I think we’d both been pretending that sex wasn’t really very important to us. We’d been married for 16 years, we snuggled together in bed, and we basically had a good relationship. But underneath, we were obviously both angry and frustrated.”

The first time he popped the little blue pill, Norm was skeptical.

“I really didn’t think it was going to work,” he says. “And also it had been so long since Maggie and I made love that the whole thing felt a little strange.”

But it did work.

“I got an erection very easily,” Norm says. “I started to go too fast for Maggie…I was so used to feeling like I had to penetrate her or I’d lose my erection. So I slowed down, and relaxed, and I was amazed that the erection just stayed there. It was great. Like the old days…maybe better.”

In the year since that first trial with Viagra, Norm says he and Maggie have made love roughly once a week, using the pill every time.

“That may not sound like much to some guys,” he says, “but it’s just right for me…and I think for Maggie too. I’ve been struggling for years with a self-image that I’m not a very good lover. I may still not be Casanova, but I’m a helluva lot more confident now than in the past.”

The Pill, Redux

Stories like Norm’s have become quite common. Introduced in 1998, Viagra has become one of the blockbuster drugs of the 21st century. About 16 million men have taken Viagra since it was introduced. In 2003 alone, the drug company Pfizer sold than $1.7 billion of the drug. And it’s not just older men with erection problems using the pills. An unknown number of younger men are using Viagra or one of the two new entries to the market, Levitra and Cialis, to enhance their normal erections, reduce performance anxiety, or simply to experiment. For example, the 26-year-old actor Ashton Kutcher has openly talked about using Viagra to enhance his sexual performance with his girlfriend, actress Demi Moore. "Man, it was like a rocket taking off from a launch pad,” he was quoted as saying. “You want to go longer than you usually do. But you lose a lot of sleep because you can't roll over."

This widespread public acceptance isn’t surprising since Pfizer has poured hundreds of millions of dollars into advertising and promotion—almost $90 million in the year 2000 alone. Similar pushes can be expected from the manufacturers of Levitra and Cialis and sales of these pills are likely to skyrocket in coming years.

Until recently, some research suggested that the already huge market for these pills might double because they treat female sexual dysfunction as well. But after spending eight years and millions of dollars, Pfizer pulled the plug on their research into the utility of Viagra in women. It turns out that although a woman’s clitoris responds in a similar way to a man’s penis, and Viagra does enhance clitoral engorgement, this did not translate into clinically significant improvement in sexual function, such as the ability to achieve an orgasm or an increased desire for sex. A few very preliminary studies, however, find that if Viagra is combined with a low dose of testosterone replacement therapy, the results for women are very satisfactory. That is undoubtedly because the testosterone boosts a woman’s libido while the Viagra increases such things as vaginal lubrication, clitoral response and other physical aspects of sexual arousal.

As someone who has seen first-hand the kind of grief that can accompany erectile dysfunction, you might think I’d be happy that erection-enhancing drugs are so widely used. In fact, I think these pills are being over-prescribed, over-used, and used by men who don’t have a clue about the real cause of erectile dysfunction.

I’m worried that men are being prescribed Viagra and its cousins without a proper look for medical conditions such as diabetes and heart disease that may be causing the erectile problems. Failing erections can be like the canary in the coal mine—an early sign of a significant medical problem. Several studies have shown a very high correlation, for example, between erectile dysfunction and risk for heart attacks or stroke. Fixing a failing erection without checking for potentially important underlying problems is like taking a painkiller for a toothache. The solution is to take care of the tooth, not just mask the pain with drugs.

I’ll look at these drugs in detail in a moment, but first it’s important for both men and women to understand how erections work and why they sometimes fail.

The Clock and Erections

The penis has a mind of its own. It can be coaxed, it can be wooed, and it can be enticed, but it cannot be ordered. As Leonardo da Vinci observed of the male organ, “Many times the man wishes it to practice and it does not wish it; many times it wishes it and the man forbids it.” All men, of course, experience times when erections fail, whether because of stress, tiredness, one drink too many, or just the unpredictable nature of sexual arousal itself. But aging—the male biological clock—definitely takes a toll on erections. That’s because, fundamentally, an erection is a matter of plumbing, hydraulics, chemistry, and nerve impulses, all of which depend on physical structures that wear out, to one degree or another, as a man ages. Fortunately, of the many ways the male biological clock can degrade sexual health, its impact on erections is today the most readily corrected.

Erectile dysfunction usually begins as a purely physical problem with blood vessels, nerves, or other parts of the male reproductive machinery. But very rapidly a complicated psychological dimension is layered onto the physical problem—which almost always makes things worse. For example, men often become increasingly anxious that they’ll lose their erection. Anxiety releases hormones such as adrenaline that clamp down on blood vessels, including those feeding the penis, thereby making an erection that much harder to obtain. Men sometimes misinterpret the reason for erectile failure (“I must not find her sexually attractive anymore”)—and women sometimes blame themselves (“I must not be sexy enough”). The result, as we saw in Norm’s case, can be a psychological domino-effect leading to less and less sex, feelings of emotional distance, abandonment, or rejection.

One of my patients, for example, a 50-year-old man who had recently re-married a woman 12 years younger than him, was having erectile problems. His teen-aged children still lived in the house, which made him feel self-conscious, and he and his new wife worked long hours, which sapped his energy and sexual performance.

“I just need a little insurance,” he told me. “I love my wife and want to make love to her. I just don’t want to have to worry about my erection.”

This man’s situation was a typical combination of natural age-related declines in performance coupled with some specific lifestyle factors and a fear of failure. For him, the erection-enhancing medication worked beautifully.

“Sometimes I don’t even need it,” he says. “Over the past few months I’ve gained enough confidence and feel relaxed enough about sex that sometimes it just happens spontaneously, which is really great.”

Not all stories about Viagra end so happily, however. If a couple has become used to not having sex because of erectile problems, it will likely take more than improved erectile function to restore a healthy, mutually satisfying sex life. Harold’s story is a good example. Harold was 67 when he came to see me about a prescription for Viagra. He and his wife hadn’t had an active sex life in many years, though he told me they still enjoyed cuddling together in bed and he felt they still loved each other deeply. Harold had read about Viagra and wanted to try it. His symptoms were classic and fairly normal: a slowly diminishing sex drive coupled with erections that were more difficult to obtain and which “wilted” faster than he would like.

“I just want to see if these pills really work,” Harold told me.

I gave him a trial packet of Viagra and he left my office with a smile on his face.

A week later Harold called me. He sounded both perplexed and annoyed.

“The pills worked, doc,” he said. “But my wife doesn’t want to have sex! She was actually angry when I tried to make love to her the other night. I was baffled…and then I got angry back and we had a big fight. She admitted that all this time we weren’t having sex was just fine with her and she didn’t like me suddenly pushing her to have sex. She said it hurt to have sex now and she just wasn’t going to do it.”

Harold was understandably frustrated, but as I questioned him more closely, I could see that his approach and behavior were contributing to the problem. He admitted that he hadn’t told his wife about the Viagra…he wanted it to seem natural. So his wife undoubtedly was surprised and somewhat confused by his sexual advances. Also, Harold didn’t understand how a woman’s reproductive organs change with age, so he couldn’t appreciate the ways he could help make sex enjoyable. I suggested that Harold be honest with his wife, that he tell her about the Viagra and why he wanted to try it, and that he not push her to have sex if she didn’t want it. I also explained that many older women have difficulty becoming sufficiently lubricated for enjoyable sex, so spending a good deal of time on foreplay and using a lubricant of some kind would help.

I’d like to report that Harold did all of this and that he and his wife resolved their differences and discovered that they enjoyed making love to each other. Unfortunately, that didn’t happen. I can’t say exactly why—I never talked to Harold’s wife, for one thing, and I don’t know how Harold actually put my advice into practice. What I know is that he called me about 10 days later and said he was giving up…that his wife thought he was being juvenile to try Viagra and that nothing he could say would change her mind.

At the end of this chapter I’ll talk more about the emotional aspects of sex and ways that couples can avoid this kind of situation. For the moment I just want to reiterate the point that fixing an erection is just a small part of the much larger puzzle that is any couple’s sexual relationship.

The Penis 101

Just as a man will be better prepared to diagnose car problems if he knows how engines work, he will be in a better position to deal effectively with ED if he knows how his penis works.

In most cases, an erection begins when the brain registers a physical or mental stimulation— such as physical touch or a sexually arousing visual or mental image. This arousal produces electro-chemical signals that travel along nerve fibers down the spinal cord to the penis. When the signals reach the penis, they trigger the release of a gas called nitric oxide, which, in turn, causes the arteries feeding the penis to relax and open up. Blood can then pump into three cylinders of sponge-like tissue inside the penis. When the chambers are fully saturated, the penis is erect. The erection is maintained because the swelling tissue squeezes shut the many small veins draining blood out of the penis. Normally, an erection lasts as long as sexual stimulation continues or until orgasm. Following orgasm, nerve signals reverse the effect on penile arteries—squeezing them shut again, which allows blood to drain out of the penis causing it to return to the flaccid state.

Erections are actually vital for penile health. Only when erect is the penis fully bathed in fresh, oxygen-rich blood. This is why healthy men have numerous spontaneous erections while they sleep—it is their body’s way of maintaining a good flow of blood to the tissues of the penis.

The normal adult penis is about three inches long when flaccid and between 4.5 and 6.5 inches long when erect. Penises that are longer than average when flaccid tend not to enlarge as much during erection, hence the size of a flaccid penis is not a good indication of its size when erect.

Boys (and men too) tend to be very concerned with the length of their penises, which is probably natural but also can cause much needless anxiety. Male actors in erotic magazines and videos notwithstanding, bigger is not necessarily better when it comes to penis size. Several facts about female anatomy are relevant here. First, vaginas have evolved to accommodate average-sized penises, meaning much beyond 6 inches of penis is of little use and may actually cause a woman pain during intercourse when the penis hits her cervix. Second, only the outer third of a woman’s vagina is richly endowed with pleasure-producing nerves. The inner two thirds is virtually numb in comparison, hence whether a man’s penis reaches to the end of the vagina or not is irrelevant to his ability to sexually satisfy his partner. Finally, the real source of a woman’s pleasure, the clitoris, isn’t in the vagina at all—it’s above the mouth of the vagina and usually requires stimulation other than mere penile penetration to produce an orgasm.

All of which simply proves the validity of the old saw that “it’s not the size of the instrument, it’s how you play the tune.” Being a good lover has everything to do with personality, technique, and experience and hardly anything to do with the size of your penis.

The nature of the plumbing supporting erections means that anything interrupting the initial opening of the penile arteries (such as cholesterol deposits inside the arteries, damage to the nerves associated with the arteries, or interruption of the nitric oxide signal in the penis) will hurt erections. Likewise, if the penile veins don’t close fully, blood can’t remain trapped in the penis long enough to sustain an erection. It’s here that aging takes its toll—nerve fibers degrade, arteries clog, and the enzymes that create nitric oxide become less robust. It’s here, too, that a wide range of prescription medications exert side effects that can interfere with erections. For example, antidepressants belonging to the family of serotonin reuptake inhibitors—of which Prozac is the most familiar—can interfere with both erectile function and the ability to achieve orgasm. In addition, some classes of high blood pressure medications (such as the thiazide diuretics and beta-blockers) also can impair male sexual functioning. Recognizing the role that common prescription medications can play in sexual dysfunction is important because alternative medications are usually available that can produce similar clinical benefits with less risk of sexual problems. If you are taking an antidepressant or beta blockers, and your sex life is affected, talk to your doctor. You might be much happier with a different prescription. Although we’ve just seen that erections can fail for many reasons, many treatments and interventions are available today to restore erections and reverse this aspect of the male biological clock.

Treating Erectile Dysfunction

In the early 1990s, pharmacologists at the drug company Pfizer were looking for a new drug to treat angina, a type of chest pain associated with constricted coronary blood vessels. They were looking for a compound that would relax those arteries and ease the pain.

Animal studies suggested that a molecule dubbed UK-92-480 might work. When they tried it on men, they found that it wasn’t terribly effective at easing angina, but did have an unusual side effect: many of the men reported getting more frequent and longer-lasting erections. The Pfizer researchers quickly shifted gears, sensing they might have in UK-92-480 the long-sought erection-enhancing pill. At that time, none of the treatments for erectile dysfunction were very natural or convenient, involving injections into the penis of erection-producing compounds, vacuum devices, or surgical implants.

It took years to conduct the necessary clinical trials for safety and effectiveness, but in 1998, UK-92-480, now dubbed Viagra, made its debut. As noted above, it has proven every bit the blockbuster the researchers hoped for.

Viagra works by blocking an enzyme that normally controls the constriction of penile arteries after the release of nitric oxide. With the enzyme blocked, the relaxation triggered by nitric oxide lasts longer and is harder to shut down. The result? Erections that are easier to create and easier to maintain.

As of this writing, three erection-enhancing drugs are available to men in the United States: Viagra, Levitra, and Cialis. All three have been shown in clinical trials to be highly effective. About 80% of men say these drugs improve their erections and about 75% of men say they allowed them to have intercourse successfully. All three cause the same range of side effects in a minority of men who use them, most commonly headache, facial flushing, runny nose, and stomach upset.

Although all three drugs work the same way (by enhancing the effects of nitric oxide) subtle differences in their molecular shapes result in differences in how long they remain effective in the body.

Viagra and Levitra are typically taken 30 minutes to an hour before sexual activity is expected and maintain their erection-enhancing effects for four to six hours. Cialis has been nick-named “the weekender” because its effects remain for roughly 36 hours, which makes timing of sexual relations less critical.

It’s important to point out that these drugs do not cause erections. Nitric oxide must be present in the penis for them to work—and nitric oxide is only produced in response to sexual stimulation (either physical or mental). This is actually something of an advantage because it’s more “natural.” The earlier treatments involving penile injections produce an “automatic” erection, which some women reported made them feel a bit left out of the sexual process.

It’s important to point out, too, that a man has to want to get an erection as well as have the ability to get an erection. Studies show that Viagra and other erection-enhancing drugs don’t work very well in men with low testosterone and, hence, low sexual desire. For these men, testosterone needs to be boosted to normal levels using any of the available strategies (covered fully in the next chapter) and then, if they still have erectile problems, an erection-enhancing medication is likely to be effective.

It’s also vital to remember that all three of these drugs can be dangerous—even lethal—if used by men who are also using certain drugs called nitrates for heart problems. In addition, if used by otherwise healthy men, the drugs can cause an excessively prolonged and painful erection, called priapism. Fortunately this is extremely rare. Because of these and other, much less common risks, none of these drugs should be taken without a doctor’s permission.

Here’s a summary of the key points about the current erection pills:

Onset of action Duration of action Recommended Dose Not suitable for Limits of Use
Viagra 30-60 min. 4 hours 50 mg to start, with adjustments up to 100 mg or down to 25 mg. depending on response. Men taking nitrate medications such as nitroglycerine Should not be used more than once a day
Levitra 25-30 min. 4-5 hours 10 mg, with adjustment to 20 mg if needed Men taking nitrate medications or alpha-blocker medications Should not be used more than once a day
Cialis 16-60 min. Up to 36 hours 10 mg, with adjustment to 20 mg if needed Men taking nitrate medications or alpha-blocker medications Should not be used more than once a day
If Pills Don’t Work

Sometimes erectile dysfunction arises from relatively severe damage to either blood vessels or nerves. Older men with diabetes, for instance, often have difficulties with erections because of nerve damage caused by long-term high blood sugar levels. Also, men who have had prostate surgery (even those who undergo so-called “nerve-sparing surgery”) often have erectile problems because of damage to nerves during the operation. In such cases, erection-enhancing pills may not be enough. The remaining options include: penile-self injection; intra-urethral suppositories; vacuum devices; and penile implants. If a man is found to have abnormally low testosterone levels, he may benefit from testosterone therapy as well (see Chapter 3 for more on this topic).

Injections are made with a short, fine needle into the side of the penile shaft. Although most men wince at the thought, the injections are virtually painless. An erection is generally obtained within minutes of the injection and can last from a half-hour to an hour. A variety of drugs are used including papaverine hydrochloride, a , and prostaglandins, and a number of different injection systems are available. The main risks of injections are priapism and scarring from repeated use.

An alternate way to deliver the medication is in the form of a tiny pellet deposited about an inch into the penis by inserting an applicator tube into the opening at the tip of the penis. The pellet dissolves and an erection will begin within 8 to 10 minutes. Discomfort is fairly common, with the most common side effects being an aching in the penis, testicles, and area between the penis and rectum; warmth or a burning sensation in the urethra; redness from increased blood flow to the penis; and minor urethral bleeding or spotting.

Mechanical vacuum devices cause an erection by creating a partial vacuum, which draws blood into the penis, engorging and expanding it. The devices have three components: a plastic cylinder, into which the penis is placed; a pump, which draws air out of the cylinder; and an elastic band, which is placed around the base of the penis to maintain the erection after the cylinder is removed by preventing blood from flowing back into the body.

If none of these methods work and the erectile dysfunction is severe, penile implants can be surgically installed. The most common implants are fluid-filled hydraulic devices that allow a man to have a modest erection at any time he wants by pumping fluid into two inflatable chambers implanted in the penis. The disadvantages of implants are their high cost, the discomfort and risks of surgery, and the fact that the erections obtained, while sufficient for intercourse, are usually not as robust as those obtained in men with less severe dysfunction who use other methods


i. Viagra Keeps Demi, Ashton Happy. Asian News International, January 30, 2004.

ii. Sharlip, D. New Therapies for Erectile Dysfunction. Medscape Urology. At Accessed February 2, 2004

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