[Paleopsych] NYT: (Erections) With New Lease on Life, Don't Miss the Fine Print
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Fri Jun 24 19:56:27 UTC 2005
With New Lease on Life, Don't Miss the Fine Print
By JANE BRODY
Only if you never watch television, read a newspaper or magazine or
listen to comedians can you have escaped the revolution that has
occurred in the treatment of erectile dysfunction.
Three drugs - Viagra (sildenafil), Levitra (vardenafil) and Cialis
(tadalafil) - have in recent years joined several older and more
invasive or involved treatments for this common condition.
Estimates of the prevalence vary, ranging from about 5 percent of men
in their 40's to over 50 percent in their 70's, depending in part on
how the disorder is defined. An estimated 15 million to 30 million
Americans have erectile problems.
But despite the unavoidable exposure to the drugs through advertising
and comedy routines, a majority of these men have never received a
medical diagnosis of erectile dysfunction, and only a small fraction
are being treated, experts report. Many men are too embarrassed to
mention the problem to their doctors, and many doctors are equally
reluctant to ask patients about it.
On the other hand, some men taking the new drugs have not been
adequately screened for possible correctable underlying causes or
medical problems that could render the drug treatment unsafe.
Problem With Many Causes
A man's ability to perform sexually can be impaired by a host of
factors, including disorders that affect nerves, blood vessels or
hormonal output; certain medications (both prescription and over the
counter); diseases like diabetes, stroke, multiple sclerosis or
epilepsy; aging; psychological problems like depression and
performance anxiety; pelvic trauma, radiation or certain operations;
and, of course, a loss of interest in one's sexual partner.
In many men with erectile dysfunction, a combination of factors are
Risk factors for cardiovascular disease - hypertension, abnormal blood
lipids, smoking and diabetes - are associated with an increased
prevalence of erectile dysfunction, strongly suggesting that men
seeking treatment first be evaluated for heart and blood vessel
This is best done with a full medical history, measurement of blood
pressure, blood sugar and blood lipids, and possibly a treadmill test.
A cardiovascular assessment is especially important for men of middle
age and older, since resumption of sexual activity after treatment can
result in a heart attack in those unaccustomed to the exertion.
Men at high risk for cardiovascular disease - those with uncontrolled
hypertension, unstable angina, severe heart failure, valve disease or
who suffered a recent heart attack or stroke - should not engage in
sexual activity and should not be treated for erectile dysfunction
until their medical problems are resolved.
Insufficient testosterone is an uncommon cause of erectile
dysfunction, affecting about 6 percent of men with this problem.
Although giving testosterone to someone with a deficiency may not in
itself correct the erectile problem, testosterone is the libido
hormone for both men and women and is an important stimulant of sexual
The new drugs are revolutionary because earlier treatments were more
complicated. One very effective agent, alprostadil, must be
administered directly into the urethra or injected into the penis. The
injections, which are more effective, can help men with a variety of
underlying causes, both psychological and physical. In one study, more
than 80 percent of men and their partners reported satisfactory
Another treatment, vacuum constrictor devices, use vacuum pressure to
promote blood flow into the penis and a constricting ring to keep the
blood from escaping. Though it works in about two-thirds of cases, it
does prevent ejaculation.
A third approach involves an implanted prosthesis. One kind is a
semirigid rod that, in effect, creates a permanent erection, and the
other is an inflatable device that can readily pump up the penis when
sexual activity is desired.
To appreciate the value of the new drugs, it helps to understand how a
normal erection occurs. With sexual arousal, the penis must fill with
blood, causing it to enlarge and become rigid. For as long as arousal
persists, fibrous tissue in the penis preserves the erection by
creating a cinch to prevent blood from leaving.
In addition to a receptive state of mind, adequate levels of
testosterone and healthy blood vessels and nerves, an erection
requires the chemical messenger nitric oxide. It plays two critical
roles, transmitting arousal impulses between nerves, and relaxing the
smooth muscles in arteries, allowing them to expand and fill with
Nitric oxide signals production within artery cells of a chemical
called cyclic guanosine monophosphate (cGMP), which increases blood
flow to the penis. This chemical is broken down by another,
phosphodiesterase-5 (PDE-5), to end the erection. The new drugs all
work by inhibiting PDE-5, allowing cGMP to produce and sustain an
The three drugs are about equally effective, but there are differences
in their actions. In general, the drugs should be taken about an hour
before expected sexual activity, and none should be used more than
once a day. Viagra is best taken on an empty stomach (dietary fat
delays its effect by about an hour).
Levitra and Cialis are not affected by food, but the blood level of
Levitra is reduced by high-fat meals. None of the drugs should be
taken with alcohol, though only Cialis is said to cause dizziness when
combined with normal amounts of alcohol.
Viagra and Levitra are effective for about four hours; Cialis, for up
to 36 hours. Viagra is most effective after an hour. Levitra may work
within 20 minutes and Cialis within 45.
It is important for men and their partners to understand that these
drugs by themselves do not cause an erection or affect libido. They
work only as a result of sexual stimulation.
Are the Drugs Safe?
For men who are otherwise healthy, all three drugs are considered very
safe. But there can be side effects: headache in 10 to 30 percent of
patients; flushing in 10 to 20 percent; heartburn in 3 to 16 percent;
runny nose in 1 to 11 percent; changes in color perception in 2 to 10
percent; muscle aches and back pain in up to 10 percent; and dizziness
in up to 5 percent.
There have also been more than three dozen cases of blindness reported
in men taking Viagra and four cases in men taking Cialis. The vision
problem may stem from the same health problem that caused erectile
dysfunction. Likewise, deaths and nonfatal heart attacks have been
reported in users, but no cause-and-effect evidence has been shown.
There are also possible serious interactions with other medications,
like nitrates (including nitroglycerin pills, patches and pastes);
alpha blockers for hypertension; protease inhibitors used in AIDS
treatment; the antifungals ketoconazole and itraconazole; and the acid
Several other drugs, including rifampin, carbamazepine and phenytoin,
may decrease the effectiveness of the erectile drugs. In addition,
patients should not take Levitra if they have a heart problem called
prolonged QT syndrome.
The erectile drugs come in various dosages, and if a low dose is not
effective, a higher can often be tried. In men over 65, however, only
the lowest dosages are recommended.
Jane E. Brody can be reached at personalhealth at nytimes.com.
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