| * Please note that most treatment modalities listed below are based on conventional medicine. PreventDisease.com does not advocate the use of any pharmaceutical drug treatments. Long-term drug therapy is very detrimental to human health. All drug information is for your reference only and readers are strongly encouraged to research healthier alternatives to any drug therapies listed.
IS IMPOTENCE (ERECTILE DYSFUNCTION)?
the inability to achieve or maintain an erection sufficiently rigid
for sexual intercourse, ejaculation, or both. Sexual drive and the
ability to have an orgasm are not necessarily affected. Impotence
is medically defined as the inability to sustain an erection sufficient
for intercourse on at least 25% of attempts.
Impotence is not new in medicine or human experience, but it is
not easily or openly discussed. Cultural expectations of male sexuality
inhibit many men from seeking help for a disorder that can, in most
cases, benefit from medical treatment. The term "impotence"; comes
from Latin and means loss of power; a more accurate term is "erectile
dysfunction." The condition is normal and usually temporary, so
it is highly unfortunate that the common term for it implies a sweeping
diminution in a man's overall capabilities.
Penis and Erectile Function
of the Penis. The penis is composed of the following structures:
These structures are made up of erectile tissue . Erectile
tissue is rich in tiny pool-shaped blood vessels called cavernous
sinuses . Each of these vessels are surrounded by smooth muscles
and supported by elastic fibrous tissue composed of a protein called
- A pair
of parallel spongy columns called the corpus cavernosum
- A central
chamber called the corpus spongiosum , which contains
the urethra, the tube that carries urine from the body
Erectile Function. The penis is either flaccid or erect depending
on the state of arousal. In the flaccid, or unerect, normal penis,
the following occurs:
the following occurs:
arteries leading to the cavernous sinuses contract, reducing
the inflow of blood.
- The smooth
muscles regulating the many tiny blood vessels within the penis
are also contracted.
- The man's
central nervous system stimulates the release of a number of
chemicals, including acetylcholine and nitric oxide.
chemicals relax the smooth muscles in the penis. This allows
blood to flow into the tiny pool-like cavernous sinuses, flooding
- This increased
blood flow nearly doubles the diameter of the spongy chambers.
- The veins
surrounding the chambers are squeezed almost completely shut
by this pressure.
- The veins
are unable to drain blood out of the penis and so the penis
becomes rigid and erect.
Substances for Erectile Health
A proper balance
of certain chemicals, gases, and other substances is critical for
Collagen. Collagen is the major component in structural tissue
in the body, including in the penis. Excessive amounts, however,
form scar tissue, which can impair erectile function.
Oxygen. Oxygen-rich blood is one of the most important components
for erectile health. Oxygen affects two substances that are important
in achieving erection:
vary widely from reduced levels in the flaccid state to very high
in the erect state. During sleep, oxygen levels are high and a man
can normally have three to five erections per night, each one lasting
from 20 to 40 minutes.
suppresses transforming growth factor beta 1 (TGF-B1). TGF-B1
is a component of the immune system called a cytokine and is
produced by smooth muscle cells. It appears to stimulate collagen
production in the corpus cavernosum, which can lead to erectile
enhances prostaglandin E1. Prostaglandin E1 is produced during
erection by the muscle cells in the penis. It activates an enzyme
that initiates calcium release by the smooth muscle cells, which
relaxes them and allows blood flow. Prostaglandin E1 also suppresses
production of collagen.
Testosterone and Other Hormones. Normal levels of hormones,
especially testosterone, are essential for erectile function, though
their exact role is not clear.
A large 2000
survey suggested that nearly 620,000 American men between ages 40
and 70 experience erectile dysfunction of any degree each year,
and an estimated 20 million and 30 million men in the US have erectile
dysfunction at some point during their life.
Being older is primarily associated with impotence in most men.
At a major professional meeting in 2000, experts reported survey
results finding that 44% of men over age 50 experienced some degree
of erectile dysfunction, but less than a quarter of them discussed
their problems with a physician. Many felt this was simply an aging
problem. Nevertheless, impotence is not inevitable with age. In
another survey of men over 60 years old, 61% reported being sexually
active, and nearly half derived as much if not more emotional benefit
from their sex lives as they did in their 40s.
Severe erectile dysfunction in elderly men often has more to do
with disease than age itself. For example heart disease, diabetes,
and hypertension can cause sexual dysfunction and are more likely
to occur in older than younger men.
So many physical and psychological situations can cause erectile
dysfunction, in fact, that a man should consider brief periods of
impotence to be as normal as having a cold. In fact, a cold is one
common condition that can cause temporary impotence. It is safe
to say, then, that every man experiences erectile dysfunction from
time to time. [ See What Are Life Style and Psychologic Factors
Contributing to Erectile Dysfunction? and What are the Physical
Causes of Impotence?.]
ARE LIFE STYLE AND PSYCHOLOGIC FACTORS CONTRIBUTING TO ERECTILE
between Physical and Psychological Causes of Erectile Dysfunction
Over the past
decades, the medical perspective on the causes of impotence has
shifted. Common wisdom used to attribute almost all cases of impotence
to psychological factors. Now investigators estimate that between
70% and 80% of impotence cases are caused by medical problems.
It is often difficult to determine if the cause of erectile dysfunction
is a physical or psychologic one, or even some combination. The
following may be helpful:
every case of impotence, there are emotional issues that can seriously
affect the man's self-esteem and relationships, and may even cause
or perpetuate erectile dysfunction. Many men tend to fault themselves
for their impotence even if it is clearly caused by physical problems
over which they have little control.
impotence tends to be abrupt and related to a recent situation.
The patient may be able to have an erection in some circumstances
but not in others. Being unable to experience or maintain an
erection upon waking up in the morning suggests that the problem
is physical rather than psychological.
impotence occurs gradually but continuously over a period of
time. If impotence persists over a three-month period and is
not due to a stressful event, drug use, alcohol, or medical
conditions, then the patient needs medical attention by a urologist
specializing in impotence.
has both emotional and physical consequences that can affect erectile
function. It is among the most frequently cited contributors to
psychological impotence. Anxiety over sexual performance is often
referred to as performance anxiety and may provoke an intense fear
of failure and self-doubt. It can sometimes set off a cycle of chronic
impotence. In response to anxiety, the brain releases chemicals
known as neurotransmitters that constrict the smooth muscles of
the penis and its arteries. This constriction reduces the blood
flow into and increases the blood flow out of the penis. Simple
stress may even promote the release of brain chemicals that negatively
affect potency in a similar way.
Depression. Depression is strongly associated with erectile
dysfunction. In one study, 82% of men who reported moderate to severe
erectile dysfunction also had symptoms of depression. Depression
can certainly reduce sexual desire, but it is often not clear which
condition came first.
Problems in relationships
often have a direct impact on sexual functioning. Partners of men
with erectile dysfunction may feel rejected and resentful, particularly
if the affected man does not confide his own anxieties or depression.
Both partners commonly experience guilt for what they each perceive
as a personal failure. Tension and anger frequently arise between
people who are unable to discuss sexual or emotional issues with
each other. It can be very difficult for the man to perform sexually
when both partners harbor negative feelings.
Losing a job
or having lower income or education increases the risk for impotence.
is frequently cited as a contributory factor in the development
of impotence, mainly because it accentuates the actions of other
disorders of the blood vessels, including high blood pressure and
Alcohol has also
been implicated in causing impotence. In small doses, alcohol releases
inhibitions, but in doses larger than one drink, it can depress
the central nervous system and impair sexual function.
of Frequent Erections
deprive the penis of oxygen-rich blood. Without daily erections,
collagen production increases and eventually may form a tough tissue
that interferes with blood flow. The spontaneous erection men experience
while sleeping or awake may be a natural protection against this
ARE THE PHYSICAL CAUSES OF ERECTILE DYSFUNCTION?
Deprivation and Its Causes
most commonly occurs when the penis is deprived of oxygen-rich blood.
When oxygen levels to the penis are low, an imbalance occurs in
two important substances, TGF-B1 and prostaglandin E1:
When TGF-B1 levels
increase and prostaglandin E1 levels decrease, smooth muscles waste
away and collagen is overproduced, causing scarring, loss of elasticity,
and reduced blood flow to the penis. A number of conditions can
deprive the penis of oxygen-rich blood.
levels increase, which trigger production of collagen, a tough
protein that forms all connective tissue, including scar tissue.
- In addition,
there is a reduction in prostaglandin E1, a chemical that suppresses
collagen production and relaxes the smooth muscles to allow
blood flow resulting in an erection.
Blockage of Blood Vessels (Ischemia). The primary cause of
oxygen deprivation is ischemia, the blockage of blood vessels. The
same conditions that cause blockage in the blood vessels leading
to heart problems may also contribute to erectile dysfunction. For
example, when cholesterol and other factors are imbalanced, a fatty
substance called plaque forms on artery walls. As the plaque builds
up, the arterial walls slowly constrict, reducing blood flow. This
process, known as atherosclerosis, is the major contributor to the
development of coronary heart disease. It may also play a role in
the development of erectile dysfunction.
Medical Conditions That Contribute to Erectile Dysfunction
Diabetes may contribute to as many as 40% of impotence cases
. Between one third and one half of all diabetic men report
some form of sexual difficulty. Atherosclerosis and nerve damage
are both common complications of diabetes; when the blood vessels
or nerves of the penis are involved, erectile dysfunction can result.
High Blood Pressure. Erectile dysfunction is more common
and more severe in men with hypertension than it is in the general
population. Many of the drugs used to treat hypertension are thought
to cause impotence as a side effect; in these cases, it is reversible
when the drugs are stopped. More recent evidence is suggesting,
however, that the disease process that causes hypertension itself
is the major cause of erectile dysfunction in these men. Newer anti-hypertensive
agents, including angiotensin-converting enzyme (ACE) inhibitors
and angiotensin-receptor blockers (ARBs) are less associated with
erectile dysfunction. In fact, ARBs may be particularly effective
in restoring erectile function in men with high blood pressure who
suffer from impotence.
Parkinson's Disease. As a risk factor for impotence, Parkinson's
disease (PD) is an under-appreciated problem. It is estimated that
about one-third of men with PD experience impotence. The physical
cause of PD-related impotence is most likely an impaired nervous
system. Depression and lowered self-esteem also contribute to erectile
dysfunction in these patients.
Other Medical Conditions. Multiple sclerosis (MS), which
affects the central nervous system, also precipitates sexual dysfunction
in as many as 78% of male patients. Corticosteroids, which are common
treatments for MS, may improve sexual function. Other medical conditions
that contribute to erectile dysfunctions include spina bifida, a
history of polio, and chronic kidney failure.
Cancer and Its Treatments
cancer can damage nerves needed for erectile function. Prostate
surgery and surgical and radiation treatments for prostate and colorectal
cancers can also cause impotence. [
33, Prostate Cancer.]
Prostate Cancer Surgery (Radical Prostatectomy). The first
nationally-representative study to evaluate long term outcomes after
radical prostatectomy concluded that impotence occurs far more frequently
than previously reported. The study included more African American,
Hispanic, and young men than previously studied, although there
was little difference among ethnic groups. About 40% of the study
subjects considered sexual function a moderate to big problem, but
over 70% still said they would have the surgery again. Patients
reported postoperative impotence at the following rates depending
Sexual Impairment Rate
Bilateral nerve-sparing procedure
Unilateral nerve-sparing procedure
Non-nerve sparing procedure
A number of treatments for sexual dysfunction are available that
may help some men. [See treatment sections.]
Radiation. The side effects of radiation therapy include
most of those of surgery, but the risks for impotence and incontinence
are considerably lower. A 2000 study concluded that adjuvant radiation
therapy (given right after surgery) in moderate doses does not increase
the risk for long-term urinary incontinence or sexual dysfunction
beyond that of surgery alone.
Drug Treatments. Prostate cancer medical treatments commonly
employ androgen-suppressive treatments, which cause erectile dysfunction.
for Benign Prostatic Hyperplasia (BPH).
Surgery and drug
treatments for benign prostatic hyperplasia (BPH) can also increase
the risk for impotence, although to a much lesser degree than surgery
for prostate cancer.
4% and 10% of patients who have transurethral resection of the
prostate (TURP) and open prostatectomy for BPH report impotence
afterward. The risk is very low, however, in men who were functioning
normally before surgery.
(Proscar) has been associated with impotence in between 6% and
19% of patients. Anti-androgen agents used in BPH also cause
About a quarter
of all cases of impotence can be attributed to medications. Many
drugs pose a risk for erectile dysfunction. Some authorities go
so far as to say that nearly every drug, prescription or nonprescription,
can be a cause of temporary erectile dysfunction.
Among the drugs that are common causes of impotence are the following:
Drugs that sometimes
cause impotence include:
used in chemotherapy.
- Many drugs
taken for high blood pressure, particularly diuretics and beta
- Most drugs
used for psychological disorders, including anti-anxiety drugs,
anti-psychotic drugs, and antidepressants, especially selective
serotonin reuptake inhibitors (SSRIs). Newer antidepressants
pose fewer problems.
anti-ulcer medications (cimetidine).
drugs (including some antihistamines).
Trauma, Stress or Injury
cord injury and pelvic trauma, such as a pelvic fracture, can cause
nerve damage that results in impotence.
Bicycling. Studies have indicated that regular bicycling
may pose a risk for erectile dysfunction by reducing blood flow
to the penis.
Vasectomy. Vasectomy does not cause erectile dysfunction.
When impotence occurs after this procedure, it is often in men whose
female partners were unable to accept the operation.
(Testicular Failure). Hypogonadism in men is a deficiency in
male hormones, usually due to an abnormality in the testicles, which
secrete these hormones. It affects 4 to 5 million men in the United
States. In addition to impotence, hypogonadism causes reductions
in energy, sex drive, lean body mass, and bone density. Hypogonadism
can be caused by a number of different conditions. Among them are
Levels. Only about 5% of men who see a physician about erectile
dysfunction have low levels of testosterone, the primary male hormone.
In general, lower testosterone levels appear to reduce sexual interest,
not cause impotence. A 1999 study, however, suggests that testosterone
levels are not an accurate reflection of sexual drive.
in the pituitary or hypothalamus glands.
(inflammation of the testicles).
hypogonadism. Only a few cases of exercise-induced hypogonadism
have been identified in men, but some researchers believe certain
athletes may be at risk, including those who began endurance
training before full sexual maturity, have very low body weight,
and have a history of stress fracture.
Other Hormonal Abnormalities. Other hormonal abnormalities
that can lead to erectile dysfunction in men are the following:
hormonal causes of impotence include abnormalities of the thyroid
gland and the adrenal glands.
- High levels
of the female hormone estrogen may cause impotence (which may
occur in men with liver disease).
of the pituitary gland that cause high levels of the hormone
prolactin are particularly likely to cause impotence.
Other Erectile Abnormalities
disease is an accumulation of scar tissue within the penis
shaft. This inflammation may be associated with an injury
to the penis, but no clear information exists on its origin.
The scar tissue within the shaft often causes the penis to
curve and can make erection and intercourse difficult and
painful. The disease often goes into a type of spontaneous
remission, and some individuals are able to resume sexual
activity, although there may be scarring, which results in
problems with erection.
Treatment for Peyronie's Disease. If Peyronie's disease
is treated early, ultrasound, heat application, and anti-inflammatory
drugs may help reduce scar formation. There have been reports
that potassium para-aminobenzoate (POTABA) may be helpful.
Vitamin E has also been tried but does not seem to be very
useful. Studies are suggesting that the calcium channel blocker
verapamil may be helpful. One study used verapamil and the
steroid dexamethasone administered through a special skin
patch. More than 80% of patients reported a definite improvement
in penile rigidity. Extracorporal shock wave therapy, particularly
with verapamil, has also been used with some success. In severe
cases of scarring, the only treatment is surgery to straighten
the penis and reduce the curve. Penile implants may also be
is a sustained, painful, and unwanted erection that occurs
despite a lack of sexual stimulation. Generally, priapism
results when the smooth muscle tissue remains relaxed so that
a constant flow of blood into the vessels of the penis occurs
with no leakage back out. The development of priapism has
been associated with urinary stones, certain medications,
neurologic disorders, and, more recently, with self-injection
therapy used for impotence.
Treatment of Priapism. If priapism occurs, applying
ice for ten-minute periods to the inner thigh may help reduce
blood flow. Erections that last four hours or longer require
SERIOUS IS ERECTILE DYSFUNCTION?
be a symptom of serious medical conditions, such as atherosclerosis,
diabetes, and hypertension. It can also indicate injury, age-related
changes in tissue, or long-term effects of smoking, heavy drinking,
or unhealthy diet. Psychological effects can be significant; erectile
dysfunction can have a devastating impact on a relationship and
can cause extreme depression, which may become chronic if not treated.
When a consistent pattern of sexual dysfunction extends over a prolonged
period of time, a serious physical or emotional disorder may be
IS ERECTILE DYSFUNCTION DIAGNOSED?
typically interviews the patient about many physical and psychologic
factors. The patient must be as frank as possible for his physician
to make a diagnosis. He should not interpret these questions as
intrusive or too personal if he expects to obtain help. These questions
are very relevant and important for determining the proper approach.
Even when erectile dysfunction has a clear physical cause, relationships
and psychological factors can also have an effect.
Medical and Personal History. The physician should take a
medical and personal history and may ask about the following:
In addition the physician will ask about the patient's sexually
history, which may include the following:
- Past and
present medical problems.
or drugs being used.
- Any history
of psychological problems, including stress, anxiety, or depression.
the Sexual Partner. If appropriate, the physician might also
interview the sexual partner. In fact, including the partner in
the interview process may help the physician to better decipher
underlying causes and in turn better recommend treatment choices.
- The nature
of the onset of the dysfunction.
- The frequency,
quality, and duration of any erections, and whether they occur
at night or in the morning.
- The specific
circumstances when erectile dysfunction occurred.
- The patient's
motivation for and expectations of treatment.
problems exist in the current relationship.
should perform a careful physical exam, including examination of
the genital area and a digital rectal examination (the doctor inserts
a gloved and lubricated finger into the patient's rectum) to check
for prostate abnormalities.
Using Erectile Function Treatments
usually recommend a trial of sildenafil (Viagra) to test for an
erection response. This often can replace more invasive and expensive
tests, such as an injection of papaverine or prostaglandin E1, medications
that dilate blood vessels in the penis. After the injection in men
with normal blood circulation in the penis, an erection will occur
in 10 to 15 minutes. The physician then observes the erectile response,
curvature of the penis, and response after erection. (A 1999 study
suggested that many men with normal erectile function fail a first
injection of prostaglandin E1 because of apprehension.)
for Hormonal Abnormalities. Blood tests may be used to measure
testosterone levels and, if necessary, prolactin levels to determine
if there are problems of the endocrine system. A 1999 study suggests
that testosterone level is an inadequate measure of sexual drive
and that more research is needed to determine the value of routine
assessments of this hormone in erectile dysfunction or low sexual
drive. The physician may also screen for thyroid and adrenal gland
dysfunction. In addition, various specific tests for erectile dysfunction
can be performed.
Tests for Medical Conditions that may be Causing Erectile Dysfunction.
Evidence of other medical conditions should be sought, particularly
hypertension, diabetes, atherosclerosis, and nerve damage.
Tests that monitor
night-time erections may be used to determine if the causes of erectile
dysfunction are more likely to be psychological. Neither of the
following methods is helpful in determining a physical cause for
Snap-Gauge Test. The snap-gauge test monitors the man's ability
to achieve an erection during sleep. It is a very simple test.
A more sophisticated and more expensive device is the RigiScan
monitor, which makes repetitive measurements of rigidity around
the base and tip of the penis. This test is quite accurate but may
fail to detect mild cases of erectile dysfunction.
- When the
man goes to bed, he places bands around the shaft of his penis.
- If one
or more breaks during the course of the night, it provides evidence
of an erection. In this case, a psychological basis for the
erectile dysfunction is likely.
The penile brachial
index is a measurement that compares blood pressure in the penis
with the blood pressure taken in the arm. Problems with the arterial
flow to the penis can be detected using this method.
may be used in certain cases, but they are expensive and often limited
to younger men. Anyone considering these tests should have them
done in a specialized setting with professionals experienced in
the use of the diagnostic instruments and in analyzing the data
Dynamic Infusion Cavernosometry and Cavernosography. Dynamic
infusion cavernosometry and cavernosography (DICC) is usually only
given to young men in whom some blockage of the penis or physical
injury of the pelvic area is suspected. After an erection is induced
with drugs, the following four steps are taken:
this test and other similar imaging techniques used to determine
blood flow in the penis are currently not very effective or accurate
in diagnosing and determining treatment.
- The penile
brachial index is taken.
- The storage
ability of the penis is gauged.
- An ultrasound
of the penile arteries is performed.
- An x-ray
of the erect penis is taken.
Ultrasound. Ultrasound alone may prove to be useful in detecting
some causes of erectile dysfunction, such as leakage from blood
ARE THE GENERAL GUIDELINES FOR TREATING ERECTILE DYSFUNCTION?
The cause of
impotence dictates the mode of treatment. The first step is to define
the cause, if possible, and then try the simplest and least-risky
Before a certain treatment is prescribed, the following factors
should be considered:
No matter what
the treatment, embarking on a healthy lifestyle is the first and
critical step for maintaining and restoring erectile function.
- Any pre-existing
illnesses and medications.
- The degree
of comfort with the treatment method.
satisfaction, and safety profiles need to be considered. Experts
strongly recommend that the patient's partner be involved to
help with any necessary sexual adjustment.
Some form of psychological, behavioral, sexual, or combination therapy
is often recommended for individuals suffering from impotence, regardless
Medical and Surgical Treatments. Sildenafil (Viagra), the
first effective oral agent for erectile dysfunction, is currently
the treatment of choice for many men.
Those who cannot or choose not to take the drug still have many
other options, including the following:
successful the medical treatment is and how well it is accepted
depends, in large part, on the man's expectations and how he and
his partner both adapt to the procedure.
inserted or injected into the penis.
procedures, such as penile implants or surgery (limited to those
for whom other treatments haven't worked and who have been carefully
LIFESTYLE CHANGES OR PSYCHOTHERAPIES MAY HELP PREVENT ERECTILE
cases of impotence are due to reduced blood flow from blocked arteries,
it is important to maintain the same lifestyle habits as those who
face an increased risk for heart disease.
Diet. Everyone should eat a diet rich in fresh fruits and
vegetables, whole grains, and fiber and low in saturated fats and
sodium. Because erectile dysfunction is often related to circulation
problems, diets that benefit the heart are especially important.
[For more information, see the Report #43,
Heart Healthy Diet. ]
Exercise. A regular exercise program is extremely important.
One study reported that older men who ran 40 miles a week boosted
their testosterone levels by 25% compared to their inactive peers.
Another study found that men who burned 200 calories or more a day
in physical activity (which can be achieved by two miles of brisk
walking) cut their risk of erectile dysfunction by half compared
to men who did not exercise.
Limit Alcohol and Quitting Smoking. Men who drink alcohol
should do so in moderation. Quitting smoking is essential.
active can help prevent impotence. Frequent erections stimulate
blood flow to the penis. It may be helpful to note that erections
are firmest during deep sleep right before waking up. Autumn is
the time of the year when male hormone levels are highest and sexual
activity is most frequent.
The Kegel exercise
is a simple exercise commonly used by people who have urinary incontinence
and by pregnant women. It may also be helpful for men whose erectile
dysfunction is caused by impaired blood circulation. The exercises
consist of tightening and releasing the pelvic muscle that controls
It may be several
months before the patient sees significant improvement.
the muscle is internal and is sometimes difficult to isolate,
practice first while urinating. (Once learned, however, Kegel
exercises should not be regularly performed while urinating.
Such a practice may eventually weaken the muscles.)
- Try to
contract the muscle until the flow of urine is slowed or stopped.
Attempt to hold each contraction for 10 seconds.
- Then release
about 5 to 15 contractions three to five times daily.
or Reducing Medications
are causing impotence, the patient and physician should discuss
alternatives or reduced dosages.
and Behavioral Therapy
supportive, or behavioral therapy can be of help to a patient during
all phases of the decision-making process regarding possible methods
of treatment. Therapy may also ease the adjustment period after
the initiation or completion of treatment. It is beneficial to have
the partner involved in this process. The value of sex therapy is
questionable. In one study, 12 out of 20 men whose dysfunction had
a psychological basis and who were advised to enter a sex clinic
resisted sex therapy out of embarrassment or because they felt it
wouldn't help. Of the eight who entered therapy, only one actually
achieved satisfactory sex.
ARE THE ORAL TREATMENTS FOR ERECTILE DYSFUNCTION?
is now prescribed in over 90% of erectile dysfunction cases. Studies
indicate that it helps 70% of patients achieve sexual function.
In one 1999 study, overall male satisfaction was 65%. Not surprisingly,
the best results occurred in men who had the fewest sexual problems
before treatment, but even men with severe erectile dysfunction
had a 41% satisfaction rate. A 2000 study of men who had responded
well initially to sildenafil found that 96% of them were satisfied
with the treatment after two to three years.
Administration and Effect. Sildenafil is effective within
20 to 40 minutes. The drug works only when the man experiences some
sexual arousal. Patients usually take 50 mg, although lower doses
(eg, 25 mg) may be appropriate in some groups, such as elderly patients.
Sildenafil should not be used more than once a day and the dose
should not exceed 100 mg. Used alone or in combination with penile
injections, it may help men who did not respond to initial therapy
with penile injections alone, but side effects can be quite intense
when the combination is used.
Mechanism of Actions. Sildenafil was originally developed
for heart disease, but was found to have a unique mechanism of action
that targeted only factors in the penis. The drug blocks the enzyme
phosphodiesterase-5 (PDE5). This action maintains persistent levels
of cyclic GMP, a chemical that is produced in the penis during sexual
arousal and which is the primary chemical that relaxes smooth muscles
and increases blood flow.
Common Side Effects. Common side effects include the following:
of Viagra have raised somewhat greater concern:
for Viagra. Viagra is a good choice for any man in good health
who does not have conditions that preclude taking it. Studies are
indicating that sildenafil is also safe and effective for many men
who have the following medical conditions:
Effects. About 2.5% of men experience abnormal visual effects
that include seeing a blue haze and temporary increased brightness.
Experts believe that visual disturbances are related to the
inhibition of phosphodiesterase enzymes, but the effect appears
to be temporary and insignificant. Still, men at risk for eye
problems and who take sildenafil regularly should have frequent
eye examinations with an ophthalmologist.
Interaction with Nitrate Drugs. Taking sildenafil along
with nitrates can cause a sudden and dangerous drop in blood
pressure, and the effects have been fatal in some men. No one
taking nitrates, including nitroglycerin or the street drug
amyl nitrate, should take sildenafil. In men with normal blood
pressure and in those taking other antihypertensive medication,
sildenafil causes modest decreases in blood pressure and very
small changes in heart rate, but does not appear to pose a significant
with Other Drugs. Other drugs that may have interactions
with sildenafil include certain antibiotics, such as erythromycin,
and acid blockers, such as cimetidine (Tagamet).
of Priapism. The drug poses a very low risk for priapism
in most men. (Priapism is sustained, painful, and unwanted erection.)
Exceptions are young men with normal erectile function who take
of Urinary Tract Infections in Female Sexual Partners. One
medical center reported an unusually high incidence of urinary
tract infections in female sexual partners of men who were taking
sildenafil. Older women who experience vaginal dryness may be
at higher risk for this effect if they are experiencing a sudden
increase in sexual activity.
One study reported
that sildenafil was successful in achieving erections in almost
two thirds of patients with severe erectile dysfunction due to medical
conditions that included high blood pressure and diabetes.
- Type 1
or 2 diabetes.
heart disease, with symptoms responsive to drug therapy, but
not taking nitrates.
requiring chronic dialysis.
Viagra may also help restore erectile dysfunction in some men with
the following conditions:
Candidates. Studies have not yet been conducted using sildenafil
in men with high-risk medical conditions. Men with the following
conditions should not take Viagra without the recommendation of
their physicians and even then should use it with caution:
therapy for local prostate cancer.
cord injury with some erectile response.
radical prostatectomy. Viagra may help restore potency in an
average of 30% of patients who have had radical prostatectomy.
In one study it had an 80% success rate in younger men who were
potent before surgery and who had bilateral nerve sparing procedures.
(The rate was 40% with only unilateral procedure.) It may take
nine months or longer to respond to the drug, so men might benefit
from alprostadil injections starting right after surgery to
preserve elasticity and help prevent scarring. It is unlikely
to be effective for men over 55 who had unilateral or no nerve
heart disease, such as unstable angina, a history of heart attack,
or arryhthmias. Viagra increases nerve activity associated with
cardiovascular function, especially during physical and mental
stress. Men with heart disease may benefit from an exercise
test to determine whether resuming sexual activity increases
their risk of a heart attack.
history of stroke.
(very low blood pressure).
pigmentosa. (With this genetic disease, people do not produce
phosphodiesterase-5 and do not respond to Viagra.)
Generation PDE5 Inhibitors
investigating a newer version of drugs that inhibit the enzyme targeted
by Viagra, phosphodiesterase-5 (PDE5).
Cialis. Cialis (IC351) is a potent and highly-selective PDE5
inhibitor and may not affect other parts of the body, including
the brain, heart, kidney and eyes. Clinical trials are reporting
significant success rates in up to 88% of patients. It appears to
take effect in 15 minutes and the effects last up to 24 hours. Improved
results were reported in men suffering from erectile dysfunction
of varying severity and causes. Common side effects include headache,
muscle pain, stomach upset following meals, and back pain.
Vardenafil. Vardenafil is another PDE5 inhibitor currently
being investigated. A small study concluded that it increased penile
rigidity and tumescence. Further evaluation is warranted.
Blockers for Men with Hypertension
known as angiotensin-receptor blockers (ARBs), also known as angiotensin
II receptor antagonists are being used to lower blood pressure in
men with hypertension. In one study after 12 weeks of treatment
with an ARB called losartan (Cozaar), 88% of hypertensive males
with sexual dysfunction reported improvement in at least one area
of sexuality. The number of men reporting impotence declined from
75.3% to 11.8%. Other ARBs include candesartan (Atacand), telmisartan
(Micardis), and valsartan (Diovan).
Therapy for Hypogonadism. Testosterone replacement therapy may
be effective in inducing puberty in adolescent boys with hypogonadism
and may also be helpful for some adult patients with the condition.
Some experts believe testosterone replacement therapy also may be
helpful for older men whose testosterone levels are deficient. It
may improve bone density, improve energy and mood, increase muscle
mass and weight, and heighten sexual interest.
Forms of therapy included the following:
Oral forms of
testosterone are not recommended because of the risk for liver damage
when taken for long periods of time. The drug clomiphene has been
used successfully for treating hypogonadism related to excessive
exercise. If excessive levels of the hormone prolactin cause impotence,
the drug bromocriptine (Parlodel) is sometimes helpful.
injections using testosterone enanthate (Andryl, Delatestryl)
or cypionate (Andro-Cyp, Depo-Testosterone, Virion) has been
the standard administration.
is now available as a skin patch (Testoderm, Testoderm TTS,
Androderm). Depending on the brand, patches may be applied to
the skin of the scrotum every 24 hours or to the abdomen, back,
thighs, or upper arm. In the latter case, two patches are required
every 24 hours. Testoderm and Testoderm TTS may cause less skin
irritation than Androderm. The skin patch achieves normal testosterone
levels in between 67% and 90% of men.
- A skin
gel (Androgel) is also now available, which in one study achieved
normal testosterone levels in 87% of men. A gel applied to the
penile skin is being investigated for men with hypogonadism
and erectile dysfunction. At this time, however, the gel is
applied only to the same parts of the body as the patch.
Testosterone in Men with Normal Levels. Testosterone therapy
is not recommended for men with testosterone levels that are normal
for their age group. In such men, replacement therapy does not appear
to have any benefits for increased bone mass or muscle strength.
There is also some concern that replacement therapy in men with
normal testosterone levels may increase the risk for the following
sulfate (DHEAS) is a male hormone used in the production of testosterone.
Levels of this hormone decrease as a man ages. In a 2000 study,
men under 60 years old with erectile dysfunction tended to have
lower DHEAS levels than their peers. In one small study, those who
took DHEAS for 16 weeks experienced some improvement in erectile
dysfunction. It is available as a supplement, but should not be
taken without the recommendation of a physician. The long-term effects
of this potent hormone are unknown, and may be similar to those
of testosterone replacement.
HDL (the so-called good cholesterol).
growth of prostate tumors in men with existing prostate cancers.
(Although some studies indicate that taking testosterone does
not increase the risk for prostate cancer, some experts remain
cause sleep apnea.
increased risk for polycythemia, an abnormal increase in red
increased risk for benign prostatic hyperplasia.
Phentolamine is an agent that has been in injections for achieving
erection. The drug blocks adrenaline (epinephrine), which dilates
blood vessels. An oral form of phentolamine (Vasomax) has been developed
that may be of some benefit for men with mild impotence. The drug
is not as effective as sildenafil (Viagra), but it does not interact
with nitrates. In some studies, it was effective in producing erections
within 20 to 40 minutes in 40% to 50% of men with mild to moderate
erectile dysfunction. Side effects include nasal congestion, headache,
light-headedness, low blood pressure, tachycardia (increased heart
rate), and nausea.
Apomorphine. Apomorphine (Uprima) causes a sexual signal
in the brain to trigger an erection, although it is not an aphrodisiac.
Studies report improved erectile function in 40% to 60% of men,
with the better results occurring at the higher doses. High doses,
however, also cause more severe side effects, including nausea (in
about a third of patients), yawning, fatigue, dizziness, sweating,
excitability, and aggression. Apomorphine appears to be safe for
men with diabetes, stable heart disease, and is well tolerated by
men with high blood pressure.
Melanotan II. Researchers are investigating drugs that are
derived from a natural substance released in the brain called alpha-MSH,
which increases sexual behavior. One such agent called Melanotan
II is showing promise in investigative studies. In one study, 60%
of men achieved erections after injections of Melanotan II, but
about 20% of men experience severe nausea. It appears to increase
sexual desire and takes over an hour to take effect.
Other Areas of Investigation. Investigators are also looking
at agents that might target very specific elements in the erectile
Designed Agents. Genetically designed agents for erectile dysfunction
are being investigated. One agent uses a gene that enhances
specific channels that carry potassium to the smooth muscle
cells of the penis, which may relax these muscles and achieve
Research is being done on proteins called immunophilins, which
may play a positive role in regenerating nerves in the penis
after an injury.
Inhibitors. The amino acid arginine is a key ingredient in erectile
function. It is converted into nitric oxide, which relaxes smooth
muscles. Research indicates that the enzyme arginase can disrupt
this chemical process and prevent sexual arousal in both men
and women. Researchers have identified arginase inhibitors,
an amino acid derivative called S-(2-boronoethyl)-L-cysteine
(BEC) and (S)-2-amino-6-boronohexanoic acid, which may prove
to be the basis for therapies.
ARE INJECTION AND TOPICAL TREATMENTS FOR ERECTILE DYSFUNCTION?
topical therapies employ various agents that have properties that
help achieve erection. The standard agents used include the following:
A 2000 study
examined a progressive injection protocol that starts with a less
complex and expensive combination of drugs and advances to more
complex and costly regimens until positive results, if any, are
achieved. The drugs used in the study's protocol are papaverine,
phentolamine, prostaglandin E1, and another agent, atropine sulfate.
The logic behind the protocol is to find the least costly and complex
therapy that works for the patient. Positive response rates were
as high as 97.6%. Although any or all of these agents are very effective,
injections or other invasive methods of administration are awkward
and uncomfortable. Topical forms of some of these agents are showing
derived from a natural substance, prostaglandin E1, and acts by
opening blood vessels. It is an effective alternative treatment
for some men. It can be administered in three ways:
Regardless of how it is administered, alprostadil works in many
men with a wide range of medical disorders related to erectile dysfunctions,
including the following:
- By injection
into the erectile tissue of the penis (Caverject, Edex).
- By a device
that administers the drug through the urethra (MUSE system).
- In a topical
cream (Topiglan, Alprox-TD).
not an appropriate choice for the following individuals:
of Most Alprostadil Methods. Certain side effects are
common to all methods of administration, although they may differ
in severity depending on how the drug is administered:
- Men with
severe circulatory or nerve damage.
- Men with
bleeding abnormalities or men who are taking medications that
thin the blood, such as heparin or warfarin.
- Men with
each method has other specific side effects. [ See discussions
of individual methods below].
- Pain and
burning at the application site. In one study half of the men
with injected alprostadil experienced some burning and pain
at the injection site.
of the penis (Peyronie's disease). Most likely with injections.
low blood pressure. Symptoms include dizziness, lightheadedness,
and fainting. If these symptoms occur, the man should lie down
immediately with his legs raised.
(prolonged erection). Possible with any method, but less chance
with the MUSE system than with injections. If priapism occurs,
applying ice for ten-minute periods to the inner thigh may help
reduce blood flow. Erections that last four hours or longer
require emergency care.
on female partners. Women partners may experience vaginal burning
or itching. The drug may have toxic effects if it reaches the
fetus in pregnant women, so men should not use alprostadil for
intercourse with pregnant women without the use of a condom
or other barrier contraceptive device.
Injected Alprostadil. Injected alprostadil (Caverject, Edex)
employs a very small needle that is injected into the erectile tissue
of the penis. About 80% of men report the pain of administering
the injection as being very mild. Edex is a newer and less expensive
form of injected alprostadil. In one study of 894 patients, Edex
injections achieved erections in 95% of attempts after 12 months.
There is some evidence that the agent may have long-term benefits
on smooth muscles and some men report some return to spontaneous
erections after long-term use.
The drug should not be injected more than three times a week or
more than once within a 24 hour period.
Specific reports of the severity of side effects using injections
include the following:
In spite of its
general success, self-injection therapy has a high dropout rate
and is less likely to be used now that oral treatments are available.
The primary reasons for dropping out are the following:
- Pain and
burning at the injection site. Half of men reported this side
effect in one study. To help prevent this side effect, experts
in one study recommended a lower starting dose of 2.5 micrograms
with subsequent doses increasing by increments of 2.5 until
an erection is achieved. In this study there were only two episodes
of pain out of 138 injections. (Usually, patients start with
a dose of 20 micrograms.)
Studies report that up to 4% of men using injection therapy
experienced erections lasting more than four hours, but most
cases resolve without treatment.
(Peyronie's disease). This occurs in almost 8% of cases of those
taking injection therapy for more than a year. Treatment can
be resumed when the condition resolves.
The MUSE system delivers alprostadil through the urethra. It
works in the following way:
- Loss of
interest in the procedure.
objection or relationship breakup.
improvement in erections.
- Side effects
(reported as being severe enough to withdraw by 10% of men in
- Lack of
effectiveness (14% in one study).
Studies on success
rates have ranged widely, and in one study, only 18% of men requested
additional refills. One expert believes that these less than optimal
results may be due to the physician's failure to discuss the procedure
with the patients and their partners.
- The device
is a thin plastic tube with a button at the top.
- The man
inserts the tube into his urethral opening right after urination.
(Urinating or urine leakage right after administration may reduce
the amount of medication.)
- He presses
the button, which releases a pellet containing alprostadil.
- The man
rolls his penis between his hands for 10 to 30 seconds to evenly
distribute the drug. To avoid discomfort, the man should keep
the penis as straight as possible during administration.
- The man
should be upright, either sitting, standing or walking for about
10 minutes after administration. By that time, he should have
achieved an erection that lasts between 30 to 60 minutes. (If
a man lies on his back too soon after administration, blood
flow to the penis may decrease and the erection may be lost.)
- The erection
may continue after orgasm.
Specific reports of side effects using the MUSE system include the
The MUSE system
should not be used more than twice a day and is not appropriate
for men with abnormal penal anatomy.
in the Urethra. About 10% to 17% of MUSE administrations result
in a burning sensation in the urethra that can last five to
fifteen minutes. (This pain is generally mild to moderate, however,
and is not a primary reason for discontinuing.)
Pain. Some pain in the penis occurs in about a quarter to a
third of cases; it is usually mild.
- Low Blood
Pressure. About 3% of patients experience low blood pressure.
- Drug Interactions.
Taking certain cold and allergy remedies may offset the effects
of the MUSE-administered drug.
Side Effects. Other side effects include minor bleeding or spotting,
redness in the penis, and aching in testicles, legs, and area
around the anus.
Topical Cream. Alprostadil is being developed as a topical
cream or gel (Topiglan, Alprox-TD). The cream is applied to the
tip of penis 15 minutes before intercourse. Studies are reporting
an efficacy rate of 40% to 75% and no significant side effects.
The most common one reported is a burning sensation at the application
site. The consequences to the female partner are not known.
Using Papaverine and Phentolamine
Until the introduction
of alprostadil, the two drugs used for injection therapy had been
papaverine (Pavabid, Cerespan) and phentolamine (Regitine). Adverse
reactions are usually minor but include pain, ulcers, and prolonged
erections (priapism), which sometimes require a needle to withdraw
blood or another drug to reverse the process. In a 2000 study, a
combination of these two drugs produced a much higher drop out than
alprostadil alone or a triple combination of all three.
Comparisons between Injection Therapy and Other Treatments
Comparison with MUSE System. In a 2000 study comparing alprostadil
injection and the MUSE system, injection was preferred by more men
and their partners. Edex was more successful in achieving erections
sufficient for intercourse (82% versus 53%).
Comparison with Viagra. Penile injections have now largely
been replaced by oral medications, specifically Viagra. Nevertheless,
in one 2000 study comparing injections with Viagra, 43.6% of men
who responded to the injections reported that they were more effective
than Viagra and about half of these men opted for injections rather
than medication. In another 2000 comparative study, about a third
of the men selected penile injections over Viagra.
PROCEDURES OR DEVICES ARE USED FOR ERECTILE DYSFUNCTION?
or external management systems, are effective, safe, and simple
to use for all forms of impotence except when severe scarring has
occurred from Peyronie's disease. Devices include Erecaid, Catalyst,
and the VED pump and are available over the counter.
Using the Device. Patients must receive thorough instructions
in the proper use of such devices. They typically work as follows:
Lack of spontaneity
is this method's only major drawback. The erection involves only
part of the penis shaft, and the process will certainly seem peculiar
in the beginning. When these psychological obstacles are overcome,
many couples find the result highly satisfactory.
- The man
places the penis inside a plastic cylinder.
- A vacuum
is created, which causes blood to flow into the penis, thereby
creating an erection.
- A band
is tightly secured around the base of the penis, which retains
the erection, and the cylinder is removed.
- It takes
about three to five minutes to produce an erection.
Success Rates. Studies have found that success with the vacuum
device is equal to other methods. Between 56% and 67% of men using
it reported the device to be effective. In one study of men who
had used the vacuum device for many years, almost 79% reported improvement
in their relationships with their sexual partners, and 83.5% said
they had intercourse whenever they chose. Nevertheless, drop out
rates are high. In one 1999 study, for example, the overall drop
out rate was 65%. Even in a high-success group, over half stopped
Side Effects. Side effects include blocked ejaculation and
some discomfort during pumping and from use of the band. Minor bruising
may occur, although infrequently. It is very important to use a
medically approved pump. There have been reports of injury from
vacuum devices bought through catalogues that do not have a pressure-release
valve or other safety elements.
that trap blood within the penis are also available. They are called
venous flow controllers or simple constricting devices. These devices
are typically rubber or silicone rings or tubes (eg, Actis) that
are placed at the base of the erect penis to trap the erection.
They can be used by men who can achieve erections but lose them
easily. These devices should not be used for longer than 30 minutes
or lack of oxygen can damage the penis, and they should not be used
by patients who have bleeding problems or are taking anticoagulants
Three types of
surgical implants are currently being used for the treatment of
is irreversible. Erectile tissue is permanently damaged when these
devices are implanted. Mechanical breakdown can occur, and a less
than optimal quality of erection may result. According to a 2000
study, alprostadil via the MUSE system may restore or improve the
function of a penile prosthesis in patients with a failed device.
In spite of concern about silicone implants in women, there have
been no reports of immunologic disorders in the 20 years these implants
have been used in men. Although more than 200,000 implant procedures
were performed between 1982 and 1989, this is now the least popular
therapy for erectile dysfunction.
- A hydraulic
implant consists of two cylinders placed within the erection
chambers of the penis and a pump. The pump releases a saline
solution into the chambers to cause an erection, and removes
the solution to deflate the erection.
- A penile
prosthesis is composed of two semi-rigid but bendable rods that
are placed inside the erection chambers of the penis. The penis
can then be manipulated to an erect or non-erect position.
- A third
implant uses interlocking soft plastic blocks that can be inflated
or deflated using a cable that passes through them.
Infection. Infection may be the major cause of penile implant
failure. Some experts believe that almost any intermittent pain
that continues to occur after an implant is due to an infection,
usually low-grade. Redness and fever often accompany a full-blown
infection. If the infection can be caught early enough, implant
failure can be prevented. Most infections are caused by Staphylococcus,
which is treated with antibiotic therapy for at least 10 to 12 weeks.
If antibiotics fail, a surgical exchange, in which the infected
implant is simultaneously replaced with a new one, should be considered.
This is a complex procedure, but some surgeons have reported a 90%
For men whose
impotence is caused by damage to the arteries or blood vessels,
vascular surgery might be an option. Two types of operations are
available: revascularization (or bypass) surgery, and venous ligation.
The American Urologic Association stresses that vascular surgery
is still investigative.
Revascularization. The revascularization procedure is affected
by taking an artery from a leg and then surgically connecting it
to the arteries at the back of the penis, bypassing the blockages
and restoring blood flow. Young men with local sites of arterial
blockage generally achieve the best results. Candidates should have
a percentage of smooth muscle tissue of at least 29%. In studies
of selected patients there was improvement in erectile dysfunction
in 50% to 75% of men after five years.
Venous Ligation. Venous ligation is performed when the penis
is unable to store a sufficient amount of blood to maintain an erection.
This operation ties off or removes veins that are causing an excessive
amount of blood to drain from the erection chambers. The success
rate is estimated at between 40% and 50% initially, but drops to
15% over the long term. It is important to find a surgeon experienced
in this surgery.
ARE THE ALTERNATIVE TREATMENTS FOR IMPOTENCE?
agents are marketed for impotence. Very few have been studied and
some can be harmful. Some, but not all, are discussed in this report.
[ See Warning Box.]
Yohimex) has been used as folk medicine for years. It appears to
improve blood flow. Studies have been inconclusive about its benefits,
but a recent analysis of seven trials reported that between 34%
and 75% of men achieved favorable results when taking 5 mg to 10
mg. Side effects include nausea, insomnia, nervousness, and dizziness.
Large doses can increase blood pressure and heart rate. One death
has been reported from taking tablets of the standard dosage (5.4
mg). More rigorous studies are needed to confirm its effectiveness,
and men suffering from anxiety or hypertension are cautioned against
its use. The American Urologic Association does not recommend yohimbine
for treating impotence, although some experts believe it is an inexpensive
and reasonable option for some men.
are substances that are supposed to increase sexual drive, performance,
or desire. Some examples include the following:
No one should
try any aphrodisiac without consulting a physician.
is a well-marketed product that contains yohimbine and three
herbal aphrodisiacs: catuaba, muira puama, and maca. It has
not been proven to be either effective or safe and interactions
with medications are unknown.
that some people claim have aphrodisiacal qualities include
chilies, chocolate, licorice, lard, scallops, oysters, olives,
and anchovies. No evidence exists for these claims and certainly
no one would ever advocate eating large amounts of such foods,
which in cases such as licorice and lard, can be dangerous.
fly, or cantharides, which is made from dried beetles, is the
most widely-touted aphrodisiac and is particularly harmful.
It irritates the urinary and genital tract and can cause infection,
scarring, and burning of the mouth and throat. In some cases,
it can be life threatening.
None of these
substances are regulated and their quality is not controlled. Any
substance that can affect the body's chemistry can, like any drug,
produce side effects that may be harmful.
- In one
small study, 78% of men who had impotence caused by impaired
blood flow regained erections after taking ginkgo. More research
root is a traditional Asian remedy for stimulating sexual function,
although no studies have been conducted on its efficacy.
- A dietary
liquid supplement called ArginMax is being hailed as a natural
sildenafil (Viagra) [ see above ]. The substance presumably
increases production of nitric oxide, a substance that relaxes
blood vessels. If ArginMax acts like sildenafil, it may also
have similar interactions with nitrates and other drugs, in
spite of claims for safety.
- An herbal
supplement sold as Vaegra has no association with the prescription
drug sildenafil (Viagra).
Alternative and Natural Remedies
In addition, any substance that can affect the body's chemistry
can, like any drug, produce side effects that may be harmful.
There have been a number of reported cases of serious and
even lethal side effects from so-called natural products.
For example, some products are marketed for improving sexual
function (Verve, Jolt) that contains gamma-butyrolactone (GBL).
This substance can convert to a chemical that can cause toxic
and life-threatening effects, including seizures and even
In addition, some so-called natural remedies have been found
to contain standard prescription medication. Most problems
reported occur in herbal remedies imported from Asia, with
one study reporting a significant percentage of such remedies
containing toxic metals. Even if studies report positive benefits,
most, to date, are very small. In addition, the substances
used in such studies are, in most cases, not what are being
marketed to the public.
The following website is building a database of natural remedy
brands that it tests and rates. Not all are available yet.
The Food and Drug Administration has a program called MEDWATCH
for people to report adverse reactions to untested substances,
such as herbal remedies and vitamins (call 800-332-1088).