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WSUS914 164th St. SE
Suite B-12 #244
Mill Creek, WA 98012
(425) 971-5822
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Sexual Dysfunction
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Fred Govier, MD
Chief of Surgery, Virginia Mason Medical Center, Seattle WA
Professor of Urology, University of Washington, Seattle WA
Watch Video
Introduction
Sexual dysfunction in the male is a very common problem that
encompasses erectile dysfunction (ED), premature ejaculation, and low
libido as its main components. This update will focus primarily on ED,
which is the most common form of sexual dysfunction in the American
Male. The Sexual Medical Society of North America has defined ED as
“the persistent inability to achieve or maintain an erection sufficient
for satisfactory sexual performance”. Erectile dysfunction is estimated
to affect approximately 30 million men in the United States and 159
million men worldwide. The Massachusetts Male Aging Studies published
in 1994 found that over half of the men age 40-70 years in the United
States has mild, moderate, or severe ED. We now know that ED is an
important indicator of subsequent cardiovascular disease and strokes.
We know that patients with ED have much higher levels of depression and
have lower self-esteem.
There are many myths associated with sexual dysfunction. Three
of the most prevalent myths are; that it is a psychological problem,
that safe, simple, and effective treatments are not available for the
majority of men, and that as a couple ages they become too old to enjoy
sexual activity. Looking at the first myth, we know that the vast
majority of ED is vasculogenic caused by diseases in the endothelial
lining of the blood vessels within the penis. This endothelial disease
is the same thing that causes the blockage of blood vessels in the
heart (heart attacks) and the blockage of blood vessels in the brain
(strokes). As to the second myth, we estimate that only 10% of the men
who have ED in the United States have been treated even though we have
very safe and effective oral preparations that will correct the problem
in approximately 70% of patients. Regarding the third myth, the
majority of couples never get too old to enjoy sexual function and
urologists have treatments for virtually all patients at any age.
Physiology and Anatomy
The male penis is composed of two cylindrical structures that
are attached to the male pelvis. Approximately 1/2 to 2/3 of the male
penile length is outside the body and the remainder is inside the body.
Blood supply to the penis comes from two small arteries arising in the
male pelvis “pudendal arteries” which are lined with endothelial cells
and smooth muscle. This artery courses through the pelvis and directly
into the penis. In the flaccid state, this artery is only 0.5-0.8 mm in
diameter. During the erect state, when the artery is relaxed by
chemical reactions, the artery enlarges to 1-1.5 mm and the blood flow
increases by a factor of 4.
Nerve impulses originate from the brain and travel down the
spinal cord, run alongside the prostate, and then enter the penis. When
stimulated, these nerves release a variety of chemicals that cause the
endothelial cells and smooth muscles within the arterial walls and the
penis to relax.
Within the penis are millions of sinusoidal spaces lined by
endothelial cells and smooth muscle. When the male is not stimulated,
the arteries leading to the penis are constricted, as are the
sinusoidal cells within the penis. When the male becomes excited, the
nerves fire and release chemicals that causes the smooth muscle to
relax. As the arteries relax and open, the blood flow to the penis
increases dramatically. As the sinusoidal cells relax, the blood is
trapped within the penis and a rigid erection results. In the vast
majority of men, diseases in the endothelial lining and smooth muscle
is what leads to erectile dysfunction.
Evaluation and Treatment Options
DiagnosisThe introduction of Viagra™ has revolutionized the
diagnosis and treatment of ED. Since it’s introduction, more than 7
million men worldwide have been successfully treated. The name
recognition that Viagra™ has enjoyed in two short years puts it on
level footing with products such as Coca-Cola in the world arena. In
most cases, the evaluation and treatment of ED can be done in a single
visit with your urologist. A detailed history and physical makes the
diagnosis of ED and looks for reversible causes. Blood tests need to be
done to confirm a normal level of male hormone (testosterone), assess
your risk of other cardiovascular diseases (cholesterol, HDL, LDL) and
to assure that you do not have renal disease, diabetes mellitus, or
prostate cancer (metabolic screening profile and PSA). Assuming that
you are on no form of nitrate medications (used for control of
cardiovascular disease) and you do not have severe cardiovascular
disease you may be given a prescription for Viagra™, Vardenafil
(Levitra™) or a newer five phosphodiesterase inhibitor such as
Tadalafil (Cialis™) which should be approved in early 2004. Only if
those medications are ineffective will you require further testing
and/or need to consider other treatment options.
Medical Therapy
Phosphodiesterase InhibitorsThe compelling safety and success of
Sildenafil (Viagra™) have propelled this class of drugs to the
forefront in treating ED. The phosphodiesterase (PDE) inhibitors are a
class of drugs first tested to prevent cardiac spasm and heart attacks
in men. While these drugs, which are specific for the PDE 5 isoenzyme,
were only moderately successful for preventing cardiac spasm, their
effect on improving male erections have changed the history of ED.
These drugs work by inhibiting a specific isoenzyme (PDE 5) in
the penis through a series of complex chemical reactions, which
eventually causes a better and more complete relaxation of the smooth
muscle and thus a better erection. Side effects are typically caused by
the presence of PDE 5 isoenzymes in blood vessels outside of the penis,
resulting in headaches and/or flushing and cross over with other PDE 5
isoenzymes (PDE 6), which can cause a “blue haze” in the vision of a
small number of individuals. Currently, three different drugs are
approved in the United States: sildenafil (Viagra™), vardenafil
(Levitra™), and tadalafil (Cialis™). All of the PDE 5 inhibitors block
exactly the same enzyme and should theoretically have exactly the same
effectiveness in treating ED. All three drugs will require sexual
stimulation and will all be contraindicated with any form of nitrate
use or severe cardiac disease. The differences will be in absorption,
metabolism, and side effects of the drugs.
Sildenafil (Viagra™)
Sildenafil (Viagra™) is taken in a dose of 50-100 mg and its
onset of action is 30 minutes to 1 hour after ingestion. It typically
is effective for approximately 4-5 hours and its absorption is impaired
if taken after a fatty meal. The primary side effects are headaches,
flushing, and nasal congestion. In a small number of individuals a
visual “blue haze” is noted. It has a proven record of safety and
success in more than 10 million men. There is a precaution against
using this drug within four hours of taking an alpha-blocker.
Vardenafil (Levitra™)
Vardenafil (Levitra™) appears to be a very similar molecule to
Viagra™. Its onset of action is 30 minutes to 1 hour and its duration
is approximately 4-5 hours. Its absorption after a fatty meal is also
somewhat impaired. The main side effects include headaches, flushing,
and nasal congestion. Its incidence of “blue haze” is less than that of
Viagra™. This drug is contraindicated for use with any of the
alpha-blockers.
Tadalafil (Cialis™)
Tadalafil (Cialis™) is taken in a dose of 10 or 20 mg. The
onset of action is 30 minutes to 2 hours, but the duration in the
majority of patients is up to 36 hours. Food intake has no effect on
absorption and the incidence of “blue haze” is less than 0.1%. The
primary side effects are headaches, flushing, nasal congestion, and
occasional low back pain. It can be safely used with 0.4mg of tamulosin
(Flomax™), but is contraindication with any of the other
alpha-blockers.
Non-Medical Therapy
If the PDE 5 inhibitors are ineffective or are contraindicated,
there are other very successful treatment options for men with ED.
There are a variety of non-surgical vacuum devices available to
patients. These types of devices will treat all forms of ED and are
very safe. The downsides would be the time required to utilize them as
well as the “muss and fuss” of jellies, rubber occlusive devices, and
pumps.
MUSE™ is a small pellet, about the size of a grain of rice
that is inserted into the male urethra. The pellet contains a chemical
called Prostaglandin E-1, which is a smooth muscle relaxer. The
medication is absorbed through the urethra into the penis, causing an
erection within approximately 5-15 minutes. In those patients that are
using nitrates, this is often a good form of therapy. Its side effects
include mild urethral burning.
Penile injections involve a single chemical or multiple chemicals being
injected into the penis with a very small insulin needle. These
treatments work in approximately 70-80% of all patients, but they do
require an injection for each use. Currently there is only one FDA
approved injectable on the market, Alprostadil (Caverjet™). Other
single agents such as Papaverin, Phentolamin, or mixtures of all three
chemicals (Tri-Mix) have been effective in large numbers of patients,
but they have to be used “off-label”. The advantages of these
preparations are a very quick and rigid erection. The disadvantages are
the injection itself, as well as penile scaring and a small risk of
prolonged erections.
Another option, especially for patients with more severe
vascular disease, is a surgically implanted penile prosthesis. There
are currently 2 companies that manufacture these devices in a variety
of types. The type most commonly placed in the United States is a fully
inflatable model. These devices have the advantages of allowing the
patient to look completely normal with or without and erection. When
the patient desires an erection he pumps a small bulb located within
the scrotum, which creates a completely normal appearing erection with
normal sensation and a normal ability to ejaculate and climax. These
devices are effective in approximately 95% of patients. They can be
placed through a single 1-inch incision in about 45 minutes as an
outpatient procedure. The patient does require pain pills for a week
after implantation and cannot use the devices for a 6-week period. On
average these devices last approximately 12-14 years. The downsides to
these devices are the costs involved, the need for a surgical
procedure, and a low risk of infection and mechanical complications.
Conclusion
Erectile dysfunction is a very common condition in the United
States that dramatically affects the patient’s well being and quality
of life. It is almost always caused by vasculogenic factors and is
typically easy to treat. It is important to diagnosis this condition,
as it is a predictor of cardiovascular disease. The evaluation and
treatment can typically be done in a single office visit with minimal
testing. Safe, effective oral preparations are available and
appropriate in the majority of patients. In the event that oral
preparations are contraindicated or are not effective, we have a
variety of other therapeutic options that will allow virtually all
patients to enjoy a healthy, fulfilling sexual relationship again.
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