Since
its introduction in 1998, sildenafil — better known
by its trade name Viagra — has been one of the most
popular prescription medications on the market. It is
the first "as needed" pill treatment for erectile dysfunction
(also called impotence
), a problem that may affect up to 30 million American
men. Although a number of other treatments are available,
Viagra has the advantage of being simple, effective
and generally safe. If you or your partner is thinking
about using Viagra, the following information may help
you decide if this treatment is right for you.
What
is Viagra?
Viagra is a prescription medication that helps men
with erectile dysfunction to achieve and maintain an
erection. It is taken as a pill, usually one hour before
you anticipate engaging in sexual activity.
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How
does Viagra work?
A normal erection is more complicated than it may
seem. During sexual arousal, the brain sends signals
to the penis via nerves that travel through the spinal
cord. These nerves trigger changes in blood vessels,
which allow blood to flow into the penis but prevent
the blood from draining out. The accumulation of blood
in the penis causes the penis to enlarge and stiffen.
After ejaculation, the vessels in the penis relax, and
blood drains out. Any disease or injury that interferes
with this complex process — such as damage to the blood
vessels or nerves — may cause erectile dysfunction.
In
most men, erectile dysfunction is caused by inadequate
flow of blood into the penis. Viagra works by helping
the blood vessels relax, which increases blood flow.
It does not cause an erection without sexual stimulation,
and the penis will return to its normal size and flaccid
state after ejaculation. It also has no effect on sexual
desire (libido) and does not change sensation in the
penis.
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Is
Viagra effective?
Viagra is very effective. In some studies, up to
70 percent of men had some improvement in erections
after taking Viagra. Viagra appears to work in men regardless
of why they have erectile dysfunction — including vascular
causes, neuropathy and even psychological causes.
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Does
Viagra work for everyone?
One in three men with mild to moderate erectile
dysfunction do not respond to Viagra. Men with more
severe erectile dysfunction (severity is based on many
factors, including frequency of erections, stiffness
and sexual satisfaction) are even less likely to respond,
particularly if the cause is nerve damage, such as that
associated with diabetes or certain types of prostate
surgery. In addition, many men have a partial response
to Viagra that does not totally restore normal erections.
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Can
women take Viagra?
Currently, the U.S. Food and Drug Administration
(FDA) has not approved Viagra for use in women. Preliminary
studies suggest that this medication is safe for women,
although its effectiveness in treating female sexual
problems is unclear. Some studies suggest Viagra may
improve the sexual response in women who have impaired
orgasm as a side effect of certain types of antidepressant
medications.
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Is
Viagra safe?
This issue is of considerable concern. Within the
first year of Viagra's release, the FDA documented the
deaths of 130 men who were taking the drug. Most of
these men died of heart disease. Some of them were taking
nitrates (nitroglycerin), a type of heart medication
that is known to have devastating side effects when
combined with Viagra. In other men, it is unclear whether
Viagra contributed to their death. One theory is that
heart problems may be triggered by vigorous sexual activity
rather than by Viagra itself.
Subsequent
studies suggest that, in fact, men with stable heart
disease may safely use Viagra. However, Viagra should
never be combined with nitroglycerin or other forms
of nitrates (such as isosorbide). This can produce a
life-threatening drop in blood pressure, even in men
without heart problems. If you seek medical attention
for chest pain and have taken Viagra within the past
24 hours, be sure to inform your doctor of this fact.
Viagra should also probably not be taken by men with
the following medical problems:
- Recent
heart attack or stroke (that is, within six months)
- Unstable
heart disease or heart failure
- High
blood pressure that is controlled only with multiple
medications
- Very
high or very low blood pressure
- Liver
or kidney disease
- Retinitis
pigmentosa (a rare eye disorder)
Men
who have multiple risk factors for heart disease (high
blood pressure, high cholesterol, diabetes) and lead
a sedentary lifestyle should consider having a stress
test if they anticipate resuming vigorous sexual activity
after starting Viagra.
If
you are unsure whether Viagra is safe for you, be
sure to discuss this frankly with your doctor. Viagra
can also interact with multiple medications other
than nitrates, so it is important to provide your
doctor with an accurate list of the medications you
take.
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What
are the side effects?
Viagra can cause a number of minor side effects,
including headache, lightheadedness, dizziness, flushing
and change in vision. A few men will be sufficiently
bothered by these side effects such that they may
choose not to use Viagra.
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Can
Viagra be abused?
Viagra is not habit forming or addictive. It does
not increase sexual desire or sexual enjoyment, other
than by helping a man to achieve and maintain an erection.
There is concern that Viagra will be misused as a
"performance enhancer" by some men who do not have
erectile dysfunction. However, there is no reason
to believe that the medication is unsafe when used
in this manner, as long as it is taken in the recommended
dosage and with the usual precautions.
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How
do I get Viagra?
Men with erectile dysfunction who would like to
try Viagra should discuss this with their doctor,
who can prescribe the drug. In most cases, your doctor
will want to review your medical history, perform
a physical examination and possibly order blood tests
to measure such things as hormone levels.
Erectile
dysfunction may be caused by a number of different
medical and psychological conditions. Some of the
causes are also causes of cardiovascular disease,
such as heart attack and stroke, so it is important
for your doctor to evaluate you for these conditions
before prescribing Viagra. In some cases, your doctor
may suggest an alternative treatment, such as testosterone
injections or psychotherapy.
There
is some concern that Viagra is such an effective treatment
that it will be used as a "cure-all" and important
treatable causes of impotence will be overlooked.
Thus, a thorough evaluation is necessary.
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How
is Viagra taken?
Viagra should be taken on an empty stomach. The
medication takes about one hour to work. The usual
dose is 50 milligrams. Some men get good results with
half that dose, whereas others need a higher dose.
The maximum dose is generally considered to be 100
milligrams.
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How
will Viagra affect my sex life?
Some couples who have not had sexual intercourse
for many years are able to resume doing so with the
help of Viagra. Usually, this is a positive experience,
and both members of a couple are able to enjoy greater
sexual satisfaction. However, some women who have
grown accustomed to not having intercourse may experience
discomfort or anxiety when intercourse is resumed.
It is thus important for couples to communicate about
sexual matters. Men who would like to resume intercourse
after a period of abstinence should be sure to discuss
this with their partner.
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Are
alternative treatments available?
Although few other treatments for erectile dysfunction
are as easy to use as Viagra, alternatives
are definitely available. Some of these treatments
— such as a penile implant — may help men who have
absolutely no response to Viagra. In addition, new
treatments are in development, including faster-acting
pills and creams applied directly to the penis.
Last
updated May 03, 2001
