Impotence
- Erectile Dysfunction (E.D)
Impotence
is a consistent inability to sustain an erection
sufficient for sexual intercourse. Medical professionals
often use the term "erectile dysfunction"
to describe this disorder and to differentiate
it from other problems that interfere with sexual
intercourse, such as lack of sexual desire and
problems with ejaculation and orgasm.
The information contained below focuses
on Impotence defined as erectile dysfunction.
Impotence can be a total inability to achieve
erection, an inconsistent ability to do so, or
a tendency to sustain only brief erections. These
variations make defining impotence and estimating
its incidence difficult. Experts believe impotence
affects between 10 and 15 million American men.
In 1985, the National Ambulatory Medical Care
Survey counted 525,000 doctor-office visits for
erectile dysfunction. Impotence usually has a
physical cause, such as disease, injury, or drug
side-effects. Any disorder that impairs blood
flow in the penis has the potential to cause impotence.
Incidence rises with age: about 5 percent of men
at the age of 40 and between 15 and 25 percent
of men at the age of 65 experience impotence.
Yet, it is not an inevitable part of aging. Impotence
is treatable in all age groups, and awareness
of this fact has been growing. More men have been
seeking help and returning to near-normal sexual
activity because of improved, successful treatments
for impotence. Urologists, who specialize in problems
of the urinary tract, have traditionally treated
impotence - especially complications of impotence
How Does an Erection Occur?
The penis contains two chambers, called
the corpora cavernosa, which run the length of
the organ. A spongy tissue fills the chambers.
The corpora cavernosa are surrounded by a membrane,
called the tunica albuginea.
The spongy tissue contains smooth muscles, fibrous
tissues, spaces, veins, and arteries. The urethra,
which is the channel for urine and ejaculate,
runs along the underside of the corpora cavernosa.
Erection begins with sensory and mental stimulation.
Impulses from the brain and local nerves cause
the muscles of the corpora cavernosa to relax,
allowing blood to flow in and fill the open spaces.
The blood creates pressure in the corpora cavernosa,
making the penis expand. The tunica albuginea
helps to trap the blood in the corpora cavernosa,
thereby sustaining erection. Erection is reversed
when muscles in the penis contract, stopping the
inflow of blood and opening outflow channels
What Causes Impotence?
Since an erection requires a sequence
of events, impotence can occur when any of the
events is disrupted. The sequence includes nerve
impulses in the brain, spinal column, and area
of the penis, and response in muscles, fibrous
tissues, veins, and arteries in and near the corpora
cavernosa
Damage to arteries, smooth muscles, and fibrous
tissues, often as a result of disease, is the
most common cause of impotence. Diseases--including
diabetes, kidney disease, chronic alcoholism,
multiple sclerosis, atherosclerosis, and vascular
disease--account for about 70 percent of cases
of impotence. Between 35 and 50 percent of men
with diabetes experience impotence. Surgery (for
example, prostate surgery) can injure nerves and
arteries near the penis, causing impotence. Injury
to the penis, spinal cord, prostate, bladder,
and pelvis can lead to impotence by harming nerves,
smooth muscles, arteries, and fibrous tissues
of the corpora cavernosa. Also, many common medicines
produce impotence as a side effect. These include
high blood pressure drugs, antihistamines, antidepressants,
tranquilizers, appetite suppressants, and cimetidine
(an ulcer drug). Experts believe that psychological
factors cause 10 to 20 percent of cases of impotence.
These factors include stress, anxiety, guilt,
depression, low self-esteem, and fear of sexual
failure. Such factors are broadly associated with
more than 80 percent of cases of impotence, usually
as secondary reactions to underlying physical
causes. Other possible causes of impotence are
smoking, which affects blood flow in veins and
arteries, and hormonal abnormalities, such as
insufficient testosterone
Patient History
Medical and sexual histories help define
the degree and nature of impotence. A medical
history can disclose diseases that lead to impotence.
A simple recounting of sexual activity might distinguish
between problems with erection, ejaculation, orgasm,
or sexual desire.
A history of using certain prescription drugs
or illegal drugs can suggest a chemical cause.
Drug effects account for 25 percent of cases of
impotence. Cutting back on or substituting certain
medications often can alleviate the problem.
Physical
Examination
A physical examination can give clues
for systemic problems. For example, if the penis
does not respond as expected to certain touching,
a problem in the nervous system may be a cause.
Abnormal secondary sex characteristics, such as
hair pattern, can point to hormonal problems,
which would mean the endocrine system is involved.
A circulatory problem might be indicated by, for
example, an aneurysm in the abdomen. And unusual
characteristics of the penis itself could suggest
the root of the impotence--for example, bending
of the penis during erection could be the result
of Peyronie's disease
Laboratory Tests
Several laboratory tests can help diagnose
impotence. Tests for systemic diseases include
blood counts, urinalysis, lipid profile, and measurements
of creatinine and liver enzymes. For cases of
low sexual desire, measurement of testosterone
in the blood can yield information about problems
with the endocrine system.
Other Tests
Monitoring erections that occur during
sleep (nocturnal penile tumescence) can help rule
out certain psychological causes of impotence.
Healthy men have involuntary erections during
sleep. If nocturnal erections do not occur, then
the cause of impotence is likely to be physical
rather than psychological. 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 questionnaire, reveals psychological
factors. The man's sexual partner also may be
interviewed to determine expectations and perceptions
encountered during sexual intercourse.
How Is Impotence Treated?
Most physicians suggest that treatments
for impotence proceed along a path moving from
least invasive to most invasive. This means cutting
back on any harmful drugs is considered first.
Psychotherapy and behavior modifications are considered
next, followed by vacuum devices, oral drugs,
locally injected drugs, and surgically implanted
devices (and, in rare cases, surgery involving
veins or arteries)
Psychotherapy
Experts often treat psychologically based
impotence using techniques that decrease anxiety
associated with intercourse. The patient's partner
can help apply the techniques, which include gradual
development of intimacy and stimulation. Such
techniques also can help relieve anxiety when
physical impotence is being treated
Drug Therapy
Drugs for treating impotence 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 approved
sildenafil citrate (marketed as Viagra), the first
oral pill to treat impotence. Taken 1 hour before
sexual activity, sildenafil works by enhancing
the effects of nitric oxide, a chemical that relaxes
smooth muscles in the penis during sexual stimulation,
allowing increased blood flow. While sildenafil
improves the response to sexual stimulation, it
does not trigger an automatic erection as injection
drugs do. The recommended dos is 50 mg, and the
physician may adjust this dose to 100 mg or 25
mg, depending on the needs of the patient. The
drug should not be used more than once a day
Oral testosterone can reduce impotence in some
men with low levels of natural testosterone. Patients
also have claimed effectiveness of other oral
drugs--including yohimbine hydrochloride, dopamine
and serotonin agonists, and trazodone--but no
scientific studies have proved the effectiveness
of these drugs in relieving impotence. Some observed
improvements following their use 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 gain potency
by injecting drugs into the penis, causing it
to become engorged with blood. Drugs such as papaverine
hydrochloride, phentolamine, and alprostadil (marked
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, sometimes can
enhance erection when rubbed on the surface of
the penis. A system for inserting a pellet of
alprostadil into the urethra is marketed as MUSE.
The system uses a pre-filled applicator to deliver
the pellet about an inch deep into the urethra
at the tip of the penis. An erection will begin
within 8 to 10 minutes and may last 30 to 60 minutes.
The most common side effects of the preparation
are aching in the penis, testicles, and area between
the penis and rectum; warmth or burning sensation
in the urethra; redness of the penis due to increased
blood flow; and minor urethral bleeding or spotting.
Research on drugs for treating impotence is expanding
rapidly. Patients should ask our consultants about
the latest advances..
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