Viagra Is Misunderstood
Despite Name Recognition

By TARA PARKER-POPE

Nearly five years ago, a diamond-shaped blue pill called Viagra was introduced to an eager public.

Since then, news organizations have written 54,678 stories about Viagra. A Yahoo Internet search for Viagra produces 1.98 million hits. Jay Leno has made 944 Viagra jokes.

More than 20 million men around the world use it regularly. In the U.S., one out of every five men over 40 has tried it. An average of nine Viagra pills are dispensed every second.

What more could anyone possibly need to know about Viagra?

Plenty. Because for all its ubiquity, Viagra is surprisingly misunderstood. We all know what it does -- and what it helps men do -- but beyond that, how much does anyone really know about the Viagra experience?

"It has the name recognition of Coke and Nike," says Harin Padma-Nathan, clinical professor of urology at the University of Southern California Keck School of Medicine. "But when you ask people about it beyond the name, they really don't understand it."

Men -- and women -- who use it rarely talk about it openly. But in the U.S., an estimated 34% of all men ages 40 to 70 -- about 20 million men -- suffer from some significant level of erectile dysfunction. Most of them, about 80%, never seek treatment.

That may change next year, when two chemically similar rivals to Viagra are expected to hit the market, further fueling interest in ways to treat erectile dysfunction. And new markets for the drug are on the horizon. Studies are showing that the drug not only can help some women, but may also work as a preventative, helping healthy men to stave off impotence.

So, from doctors who prescribe it and people who use it, here are the answers to the Viagra questions many people wonder about -- but rarely ask.

What Happens When a Man First Takes a Viagra Pill?

Absolutely nothing. Pfizer Inc., the maker of Viagra, long has said the drug isn't an aphrodisiac, but many men who take it still expect to feel something.

They don't. Among several men interviewed who have used the drug, not one of them experienced any feeling or sensation after taking the pill. The nothingness is so intense that the most common reaction is a slight panic that the drug isn't going to work.

"That was my worst fear, that it wasn't going to do anything," says Steve Brykman of Los Angeles, who tried Viagra once nine months ago, when he believed job and financial stresses were interfering with his sex life. After taking the pill, "there was nothing at all," says Mr. Brykman, 33 years old. "I just felt completely normal."

Though you may not feel anything, things are happening in the body. As the pill moves into the bloodstream, it starts to block an enzyme called PDE-5. Blocking the enzyme eventually increases blood flow to areas where PDE-5 is most heavily concentrated -- the penis, nose and skin. Diminished blood flow to the penis is the cause of most erectile-dysfunction problems.

So How Do You Get It to Start Working?

Viagra gets the blood flowing, but your brain has to be in the mood as well. "The biggest misperception is that it changes your psychology and makes you want sex," says the editor of MagicBluePill.com (http://www.magicbluepill.com/), which claims to document the experiences of real people who take Viagra. "But if you're sitting talking to Grandma and you pop a Viagra, unless you have issues, nothing's going to happen."

Viagra takes about 30 minutes to kick in. Men who don't normally have problems, or who have only mild dysfunction, say it takes only a minor stimulus -- such as the brush of a hand that wouldn't cause arousal under normal circumstances -- to trigger an erection.

For men who have serious erectile dysfunction, getting things going may still require extra effort, partly because of nervousness or embarrassment about unsuccessful past attempts at intercourse.

Because Viagra doesn't increase desire, it's not prescribed for men with desire disorders, such as a low sex drive. However, if the man has lost interest in sex because he has had problems with erections in the past, Viagra may help.

Does Taking Viagra Make a Man More Virile?

It might. A surprising new area of research is whether taking a small dose of Viagra every night works as a preventative to stave off impotence, just as people can take an aspirin a day to prevent heart attack.

Though you wouldn't think you'd get much out of Viagra while you're sleeping, it turns out that nighttime erections -- most men get three or four every night -- are crucial to maintaining potency. Because most men don't have several erections during the day, the nocturnal erection, which allows blood and oxygen to flow to the genitals, is nature's way of keeping the penis in working order. The theory is that anything that increases the intensity and duration of nighttime erections is good for long-term potency.

But don't you need a sexual stimulus for Viagra to work? You do, and the likely trigger for nighttime erections, rapid-eye-movement sleep, is said to be the strongest sexual stimulus a man can experience. The brain shuts down all other activity to the penis and the level of adrenaline, which interferes with erections, plummets.

An Italian study of 44 men gave half the men 50 milligrams of Viagra before they went to sleep. The men averaged 39 years of age and didn't have erectile dysfunction. Those who took Viagra had significantly longer and more rigid nighttime erections than the men taking a placebo.

Irwin Goldstein, a noted Boston urologist, says about 400 of his patients are using 25 mg of Viagra each night as a preventative measure. "Men say, 'I'm potent. I don't want to become impotent. Is there something I can do?' " says Dr. Goldstein. "It's a very simple strategy for preserving sexual health."

But while it makes sense in theory, whether nighttime Viagra use can prevent impotence is far from proven. Pfizer says it's studying whether nighttime Viagra use can help improve sexual function in patients who have had prostate surgery but it won't present the results until early next year.

Meanwhile, it's worth noting that the best way to prevent impotence is to keep your veins from clogging up in the first place. Don't smoke, eat healthy foods, lose weight and lower your cholesterol.

Does Viagra Work for Everyone?

No. Half the people who try it don't refill the prescription. Some doctors say the 50% dropout rate is because half the people are unsatisfied with the pill. Pfizer says that Viagra studies show the drug doesn't work for only about a quarter of people who try it, and that "interpersonal issues" probably contribute to many of the other dropouts.

"Giving somebody a good erection doesn't necessarily give somebody good sex," says Mike Sweeney, Pfizer's senior medical director of urology.

In a review of 27 Viagra trials involving 6,659 men, researchers from the Veterans Administration found that in all the studies, Viagra worked 66% of the time, compared with 25% for men taking a placebo.

But while Viagra didn't work every time, 83% of the men were able to have sex at least once during the study period, compared with 45% in the placebo group.

When marketing the pill to doctors, Pfizer advises that patients try the pill as many as eight times before giving up on it. The reason, says Pfizer, is not that it takes the pill that long to work, but that a couple who have been plagued by erectile dysfunction may need a few attempts to be comfortable having sex again.

Men who are regular users of Viagra say the pill has been a life-changing experience. Gary Haub, 52, of Irving, Texas, says he began suffering from erectile dysfunction about eight years ago. Viagra worked for him the first time he tried it, but he says the real benefit was to restore the intimacy between him and his wife.

"I didn't want to hold hands or put my arm around her at the theater," he says. "When you can't perform, you stop doing all those things. The really wonderful part about this is that, yes, the sex is there, but the neat thing is we're not afraid to touch or hold hands."

Who Is The Typical Viagra User?

He's about 50 years old and has at least one cardiovascular risk factor -- such as high blood pressure, high cholesterol or diabetes. He's married, a little bit overweight, and was unhappy with his sexual function for two or three years before asking about Viagra. He uses four to six pills a month.

What Happens if You Take Viagra and You Don't Really Need It?

Men who say they don't have any problems achieving or maintaining erections say that using Viagra dramatically changes the sexual experience, but not always in a good way.

They say taking Viagra gives them a far more rigid erection that is so intense that it's almost uncomfortable, causing them to lose some sensation and making it difficult to finally achieve orgasm. One person described the feeling like puffing your cheeks full of air and then pushing them out as hard as you can.

Others say the physical reaction happens so effortlessly that it becomes intense long before the man's own level of excitement can catch up, creating a feeling of detachment. "The disembodied feeling is a really profound feeling," says the ViagraStories.com editor, a 33-year-old San Francisco man who has used the drug three times.

Mr. Brykman, managing editor of National Lampoon, used only one of the six pills his doctor gave him, and also says he felt disassociated from the experience. He says that although physically it worked, "it didn't have anything to do with arousal. As far as excitement levels or arousal levels, it didn't live up to my expectations."

Those who have used Viagra "recreationally," however, say the drug, nonetheless, makes it much easier to sustain an erection and achieve a second erection relatively quickly after orgasm.

Pfizer balks at the notion of a recreational use for Viagra, contending that if someone can feel the effect of Viagra, then they, by definition, have lost some sexual function. And the reality is, sexual function starts to fade in the 20s.

"Viagra helps to improve erectile function which isn't optimal, " says Pfizer's Dr. Sweeney. "If you're a 20-year-old college guy with no diseases and you have great erectile function, it's not going to do anything for you. It can't make it go beyond normal."

What Happens If a Woman Takes Viagra?

A 47-year-old Cincinnati woman who uses Viagra regularly says that unlike with men, Viagra in women can cause a noticeable sensation when you take it. "I felt like there was a tingling in the pelvic area," she says. "I could almost feel the increase in blood flow. It felt like there was an increase in sensitivity."

The woman's doctor gave her Viagra after a hysterectomy made it nearly impossible to have an orgasm. She says Viagra has given her about 70% of her sexual function back. The level of orgasm "is not the same to what I had prior -- it's not as full," she says. "But it does make it easier."

Early studies of Viagra and women found it didn't work, but doctors say those studies weren't selective enough and included women with desire disorders who, like men with such problems, can't be helped by Viagra.

As with men, Viagra gets the blood flowing to the genitals in women. So for women who have difficulty achieving orgasm, vaginal dryness or a lack of sensation, arousal or engorgement, Viagra may help.

In a recent Pfizer-sponsored study of 200 women who either were postmenopausal or had undergone hysterectomies and who all suffered from some form of sexual arousal disorder, half were given Viagra and half were given a placebo. Researchers found that 57% of women taking Viagra reported improved sensation in the genital area, compared with 44% in the placebo group.

Even so, many researchers say sexual problems are far more complex in women than in men, and it's unlikely Viagra will ever work as well for women as for men.

What Are the Most Common Side Effects, and Does Everyone Get Them?

In addition to helping you have sex, Viagra often gives you a headache, a stuffy nose and a flushed, beet-red face. But nobody who uses it seems to mind that much. In studies, only about 1% of people dropped out because of side effects -- exactly the same as those who used a placebo.

One bizarre side effect is visual disturbances, including a blue-green tinge to vision, which occurs about 3% of the time. In studies, about half of men who use Viagra experience at least one side effect, and the incidence is higher at higher doses. Among men taking 100 mg of Viagra in five different trials, 23% had headaches, 17% experienced a flushed face, and 12% had upset stomach. The side effects appear to be similar for women. Side effects tend to disappear with use, though one patient said he liked the headache Viagra gave him because he knew it meant he was ready.

David Nail, 39, of West Hollywood, Calif., began using Viagra after a car accident left him with a spinal-cord injury. He says sex is actually better than before his accident and he experiences a stronger orgasm. Initially, the 50 mg of Viagra he used gave him bluish vision and a mild headache. Now he rarely gets a headache, and the vision side effect has stopped.

"I thought, 'If this is the side effect, then I'll be taking this until I'm 100,'" he says. "With Viagra, I am Superman now."

What Types of Erectile Dysfunction Are Most Easily Treated With Viagra?

Men whose erectile dysfunction is psychologically based fare best. Among that group, 91% were able to have sex one or more times during treatment. Close behind were men with vascular disease (88%) and those suffering from depression (86%). The remaining categories include men with hypertension (75%), diabetes (70%), ischemic heart disease (69%) and those who've had their prostate removed (47%).

Does Viagra Work Differently Among People of Different Races?

In the VA review of Viagra studies, Asian men had the most success with Viagra, completing 61% of attempts to have sex, compared with 24% for placebo. Ninety percent reported having sex at least once in the study period.

White men who used Viagra succeeded 45% of the time, compared with 15% for placebo, and 75% managed to have sex at least once. Few blacks were included in the studies, so the data are less meaningful, although they succeeded 53% of the time, compared with 19% for placebo, and 78% reported at least one successful attempt at sex.

Pfizer says that the drug works the same in all races, and that any apparent differences are due to health differences among the men studied. For instance, studies of Asian men included few men with diabetes, who have lower success rates with Viagra.

Has Anyone Ever Died After Taking Viagra?

Yes, but it's more likely that it was existing health problems that killed them rather than the drug.

In the nine months after Viagra was first approved, 128 people reportedly died after taking it, including 80 traced to heart attack or stroke. The general feeling among doctors is that it wasn't necessarily the Viagra, but existing cardiovascular problems that would have killed them with or without the drug.

Seven months after the drug was introduced, Pfizer changed its labeling warning doctors to use caution when prescribing the drug to men with uncontrolled high blood pressure, cardiovascular problems or history of recent heart attack. The label had always warned that the drug may increase the blood-pressure-lowering effect of nitrates, such as nitroglycerin patches or nitroglycerin tablets, which are used to treat certain heart conditions.

Pfizer maintains that most men can use the drug safely, and even cites studies that show 1% of all heart attacks are the result of sex. The company also points to a study of 5,391 men in Britain who took Viagra for an average of five months; the study found they didn't have an increased risk of heart attack or stroke. However, it wasn't randomized, so it's not conclusive.

A new study published in September contends regular use of Viagra could actually protect the heart -- but the heart benefit has been shown only in rabbits.

What Happens If I Take More Than the Recommended Dose?

The size of the dose does matter. In studies of patients who took 50 mg of Viagra, 70% reported improved erections after 12 weeks of use. But that number jumped to 82% with 100 mg, the maximum recommended dose.

If 100 mg is good, you might think 200 mg would be better, but that wasn't the case. In studies, 200 mg of Viagra didn't work any better than 100 mg.

In fact, above 100 mg, pretty much all you get out of more Viagra is more side effects. Abnormal vision is a problem only 11% of the time with 100 mg, but jumps to between 40% and 50% with 200 mg, for instance. One-quarter of men who use 200 mg experience facial flushing, while 15% report stomach problems.

There's been little study of what happens when Viagra is taken at very high doses. But in one small study of 20 healthy men who took between 200 mg and 800 mg of Viagra, 95% experienced some side effect that lasted far longer than usual. Vision problems lasted as long as eight hours among the 50% of men who experienced them. And one subject taking 600 mg reported an erection lasting five hours, a potentially harmful problem.

Do the New Erectile-Dysfunction Drugs Work as Well as Viagra?

Two new drugs, Levitra, from Bayer AG and GlaxoSmithKline PLC, and Cialis, from Eli Lilly & Co., are expected to be introduced next year. They work the same way as Viagra, blocking the same enzyme. Though it's unlikely any one works better than Viagra overall, slight chemical differences mean that if one brand doesn't work for a patient, another one might.

A 67-year-old Boston man with diabetes says Viagra only worked for him about 25% of the time, and only when taking the maximum dose of 100 mg. Even then, he says, it resulted in only a "mediocre" erection, while making him feel lightheaded and giving him headaches and an upset stomach. He recently took part in a Levitra study and was shocked by the difference. "I was very, very happy," says the man, a retired cook.

Early studies show Levitra requires a smaller dose and works faster than Viagra with fewer side effects. In Europe, where Cialis has been studied longer, the drug is dubbed the "weekend pill," because its effects last up to 36 hours.

On its Web site, Pfizer says Viagra remains effective for about four hours. But doctors say it actually lasts about twice as long. A recent study from Spain reported the drug continued working up to 12 hours after taking it.

However, it's impossible to know how the drugs really stack up. Nobody has studied them against one another, and because the studies use different participants, the results can't be compared.

-- Ms. Parker-Pope, who writes the Wall Street Journal's weekly Health Journal column, served as contributing editor of this report.