|
Impotence
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. This fact sheet 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.
^ top
How
Is Impotence Diagnosed?
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.
^ top
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 low.
While sildenafil improves the response to sexual stimulation,
it does not trigger an automatic erection as injection drugs
do. The recommended dose 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 he 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 their doctors about the latest advances.
^ top
Vacuum Devices
Mechanical vacuum devices cause erection by creating a partial
vacuum around the penis, which draws blood into the penis,
engorging it and expanding it. The devices have three omponents:
a plastic cylinder, in which the penis is placed; a pump,
which draws air out of the cylinder; and an elastic band,
which is placed around the base of the penis, to maintain
the erection after the cylinder is removed and during intercourse
by preventing blood from flowing back into the body.
One variation of the vacuum device involves a semirigid
rubber sheath that is placed on the penis and remains there
after attaining erection and during intercourse.
Surgery
Surgery usually has one of three goals:
- To implant a device that can cause
the penis to become erect;
- To reconstruct arteries to increase
flow of blood to the penis;
- To block off veins that allow blood
to leak from the penile tissues.
Implanted devices, known as prostheses,
can restore erection in many men with impotence. Possible
problems with implants include mechanical breakdown and
infection. Mechanical problems have diminished in recent
years because of technological advances.
Malleable implants usually consist of paired rods, which
are inserted surgically into the corpora cavernosa, the
twin chambers running the length of the penis. The user
manually adjusts the position of the penis and, therefore,
the rods. Adjustment does not affect the width or length
of the penis.
Inflatable implants consist of paired cylinders, which are
surgically inserted inside the penis and can be expanded
using pressurized fluid. Tubes connect the cylinders to
a fluid reservoir and pump, which also are surgically implanted.
The patient inflates the cylinders by pressing on the small
pump, located under the skin in the scrotum. Inflatable
implants can expand the length and width of the penis somewhat.
They also leave the penis in a more natural state when not
inflated.
Surgery to repair arteries can reduce impotence caused by
obstructions that block the flow of blood to the penis.
The best candidates for such surgery are young men with
discrete lockage of an artery because of an injury to the
crotch area or fracture of the pelvis. The procedure is
less successful in older men with widespread blockage.
Surgery to veins that allow blood to leave the penis usually
involves an opposite procedure- intentional blockage. Blocking
off veins (ligation) can reduce the leakage of blood that
diminishes rigidity of the penis during erection. However,
experts have raised questions about this procedure's long-term
effectiveness.
What
Will the Future Bring?
Advances in suppositories, injectable medications, implants,
and vacuum devices have expanded the options for men seeking
treatment for impotence. These advances also have helped
increase the number of men seeking treatment.
An oral form of the drug phentolamine may soon join sildenafil
in the armamentarium of noninvasive treatments for impotence.
Other treatments in the experimental stages include reconstruction
surgery for damaged veins and arteries in the penis. Whether
or not this method proves to be safe and effective, ongoing
improvements in traditional methods should continue to create
more successful and widespread treatment of impotence.
^ top
Points
to Remember
- Impotence is a consistent inability
to sustain an erection sufficient for sexual intercourse.
- Impotence affects 10 to 15 million
American men.
- Impotence usually has a physical cause.
- Impotence is treatable in all age groups.
- Treatments include
psychotherapy, drug therapy, vacuum devices, and surgery.
Resources
for More Information
Impotence Information Center
P.O. Box 9
Minneapolis, MN 55440
1-800-843-4315
Sexual Function Health Council
American Foundation for Urologic Disease
300 West Pratt Street
Suite 401
Baltimore, MD 21201
1-800-242-2383
The Geddings Osbon, Sr. Foundation
P.O. Drawer 1593
Augusta, GA 30903-1593
1-800-433-4215
^ top
|
