How is ED diagnosed?
Patient History
Medical and sexual histories help define the degree and
nature of ED. A medical history can disclose diseases that
lead to ED, while a simple recounting of sexual activity
might distinguish among problems with sexual desire,
erection, ejaculation, or orgasm.
Using certain
prescription or illegal drugs can suggest a chemical cause,
since drug effects account for 25 percent of ED cases.
Cutting back on or substituting certain medications can
often alleviate the problem.
Physical
Examination
A physical examination can give
clues to systemic problems. For example, if the penis is not
sensitive to touching, a problem in the nervous system may
be the cause. Abnormal secondary sex characteristics, such
as hair pattern or breast enlargement, can point to hormonal
problems, which would mean that the endocrine system is
involved. The examiner might discover a circulatory problem
by observing decreased pulses in the wrist or ankles. And
unusual characteristics of the penis itself could suggest
the source of the problem—for example, a penis that bends
or curves when erect could be the result of Peyronie's
disease.
Laboratory Tests
Several laboratory tests can help diagnose ED. Tests for
systemic diseases include blood counts, urinalysis, lipid
profile, and measurements of creatinine and liver enzymes.
Measuring the amount of free testosterone in the blood can
yield information about problems with the endocrine system
and is indicated especially in patients with decreased
sexual desire.
Other Tests
Monitoring erections that occur during sleep (nocturnal
penile tumescence) can help rule out certain psychological
causes of ED. Healthy men have involuntary erections during
sleep. If nocturnal erections do not occur, then ED is
likely to have a physical rather than psychological cause.
Tests of nocturnal erections are not completely reliable,
however. Scientists have not standardized such tests and
have not determined when they should be applied for best
results.
Psychosocial Examination
A psychosocial
examination, using an interview and a questionnaire, reveals
psychological factors. A man's sexual partner may also be
interviewed to determine expectations and perceptions during
sexual intercourse.
[Top]
How is ED treated?
Most physicians suggest that
treatments proceed from least to most invasive. For some
men, making a few healthy lifestyle changes may solve the
problem. Quitting smoking, losing excess weight, and
increasing physical activity may help some men regain sexual
function.
Cutting back on any drugs with harmful side
effects is considered next. For example, drugs for high
blood pressure work in different ways. If you think a
particular drug is causing problems with erection, tell your
doctor and ask whether you can try a different class of
blood pressure medicine.
Psychotherapy and behavior
modifications in selected patients are considered next if
indicated, followed by oral or locally injected drugs,
vacuum devices, and surgically implanted devices. In rare
cases, surgery involving veins or arteries may be
considered.
Psychotherapy
Experts often treat psychologically based ED using
techniques that decrease the anxiety associated with
intercourse. The patient's partner can help with the
techniques, which include gradual development of intimacy
and stimulation. Such techniques also can help relieve
anxiety when ED from physical causes is being treated.
Drug Therapy
Drugs for treating ED can be
taken orally, injected directly into the penis, or inserted
into the urethra at the tip of the penis. In March 1998, the
Food and Drug Administration (FDA) approved Viagra, the
first pill to treat ED. Since that time, vardenafil
hydrochloride (Levitra) and tadalafil (Cialis) have also
been approved. Additional oral medicines are being tested
for safety and effectiveness.
Viagra, Levitra, and
Cialis all belong to a class of drugs called
phosphodiesterase (PDE) inhibitors. Taken an hour before
sexual activity, these drugs work by enhancing the effects
of nitric oxide, a chemical that relaxes smooth muscles in
the penis during sexual stimulation and allows increased
blood flow.
While oral medicines improve the response
to sexual stimulation, they do not trigger an automatic
erection as injections do. The recommended dose for Viagra
is 50 mg, and the physician may adjust this dose to 100 mg
or 25 mg, depending on the patient. The recommended dose for
either Levitra or Cialis is 10 mg, and the physician may
adjust this dose to 20 mg if 10 mg is insufficient. A lower
dose of 5 mg is available for patients who take other
medicines or have conditions that may decrease the body's
ability to use the drug. Levitra is also available in a 2.5
mg dose.
None of these PDE inhibitors should be used
more than once a day. Men who take nitrate-based drugs such
as nitroglycerin for heart problems should not use either
drug because the combination can cause a sudden drop in
blood pressure. Also, tell your doctor if you take any drugs
called alpha-blockers, which are used to treat prostate
enlargement or high blood pressure. Your doctor may need to
adjust your ED prescription. Taking a PDE inhibitor and an
alpha-blocker at the same time (within 4 hours) can cause a
sudden drop in blood pressure.
Oral testosterone can
reduce ED in some men with low levels of natural
testosterone, but it is often ineffective and may cause
liver damage. Patients also have claimed that other oral
drugs—including yohimbine hydrochloride, dopamine and
serotonin agonists, and trazodone—are effective, but the
results of scientific studies to substantiate these claims
have been inconsistent. Improvements observed following use
of these drugs may be examples of the placebo effect, that
is, a change that results simply from the patient's
believing that an improvement will occur.
Many men
achieve stronger erections by injecting drugs into the
penis, causing it to become engorged with blood. Drugs such
as papaverine hydrochloride, phentolamine, and alprostadil
(marketed as Caverject) widen blood vessels. These drugs may
create unwanted side effects, however, including persistent
erection (known as priapism) and scarring. Nitroglycerin, a
muscle relaxant, can sometimes enhance erection when rubbed
on the penis.
A system for inserting a pellet of
alprostadil into the urethra is marketed as Muse. The system
uses a prefilled applicator to deliver the pellet about an
inch deep into the urethra. An erection will begin within 8
to 10 minutes and may last 30 to 60 minutes. The most common
side effects are aching in the penis, testicles, and area
between the penis and rectum; warmth or burning sensation in
the urethra; redness from increased blood flow to the penis;
and minor urethral bleeding or spotting.
Research on
drugs for treating ED is expanding rapidly. Patients should
ask their doctor about the latest advances.