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Male
Sexual Impotence,
Sildenafil Citrate, And Acupuncture
Joseph Wong, MD
ABSTRACT
The introduction of sildenafil citrate has revolutionized the treatment
of male sexual impotence. Yet this pharmacological approach is not without
adverse effects. This article details the various causes of impotence
and sexual dysfunction, and the acupuncture points that have been recommended
for its treatment.
KEY WORDS
Male Sexual Impotence, Sexual Dysfunction, Acupuncture, Neurotransmitters
INTRODUCTION
Biology of Sexual Function
Sexual function essentially relies on the integrity and balance of the
autonomic nervous system (Figure 1). Naturally, the biochemical mechanism
involves neurotransmitters and neuropeptides.1,2 In the central nervous
system, the neurotransmitters include dopamine,
serotonin, acetylcholine, nitric oxide, and norepinephrine, and other
neurotransmitters. Neuropeptides include corticotropin, a-melanocyte
stimulating-hormone and related peptides, opioid peptides, and oxytocin,
among other neuropeptides.
At the level of the penile tissue, neurotransmitters include norepinephrine,
acetylcholine, and nitric oxide. Neuropeptides include vasoactive intestinal
polypeptide, peptide histidine isoleucine, peptide histidine methionine,
neuropeptide Y, and endothelins. Among all these, dopamine and norepinephrine
are the major vasoconstrictors, and acetylcholine and nitric oxide are
the major vasorelaxors.
There are many causes of male sexual impotence.3 Common presentations
of sexual dysfunction include: loss of libido, erectile dysfunction,
premature ejaculation, retarded ejaculation, and orgasmic failure.
PHYSICAL CAUSES
Anatomical Abnormalities
There are many causes of male sexual impotence.3 Any congenital or acquired
physical conditions affecting the anatomical pathways of sexual function
may result in dysfunction. It is common to see physical trauma involving
the spinal cord or the pelvic areas with injuries to the penile cavernous
blood vessels.
Vascular Disorders
Any blockage of the artery around the penis, such as in artherosclerosis,
may jeopardize penile erectile function. Artherosclerosis is influenced
by risk factors including smoking, obesity, high cholesterol levels,
hypertension, and diabetes.
Metabolic Disorders
According to statistics, up to 75% of male diabetic patients may have
penile erectile dysfunction; diabetes may cause significant damage to
the cardiovascular system as well as to the peripheral nerves.4
Neurological Disorders
Diseases affecting the central nervous system, such as cerebrovascular
accidents, Parkinson's disease, and multiple sclerosis, may cause temporary
or even permanent disturbance in sexual functions. Not uncommonly, persons
with paraplegia or quadriplegia may have the same problem due to sustained
pathology in the spinal cord.
Surgical Procedures
Some men who undergo operations for prostate, colorectal, or bladder
cancer may sometimes experience impotence because of disruption of the
pudendal nerves. Radiation in these areas may have similar effects.
Alcohol and Medications
Alcohol has well-documented negative effects on both testosterone levels
and libido. Many cardiovascular medications may cause sexual potency
problems, affecting the arterial supply throughout the body, including
the penis. The medications most likely to affect potency are central
sympathomimetics, b-blockers, digitalis, a-blockers, and anti-arrhythmics.
Illegal Drugs
Street drugs such as PCP (angel dust), opiates, stimulants, psychedelics,
volatile nitrites, marijuana, diazepam, and barbiturates all have negative
effects on sexual functions.
Aging Effects
There is a gradual reduction in testosterone levels with increasing
age. The main change is a decline in the length and intensity of various
phases of the sexual response cycle.
Hormonal Dysfunction 5
DHEA (dehydroepiandrosterone) is manufactured mainly in the adrenal
cortex, and testosterone mainly in the testes in males. DHEA is regulated
by corticotropin and testosterone, by luteinizing hormone-releasing
hormone (luliberin). These hormones increase sex drive and maintain
libido. Lower levels of these hormones may result in loss of libido
and abnormal sexual behavior in males.
PSYCHOLOGICAL CAUSES
Inhibition
Inhibition can be caused by restrictive upbringing. A child's experience
of his family's attitudes toward sexuality and personal relationships
is likely to have a profound effect on later psychosexual development.
Traumatic Early Sexual Experiences
Childhood sexual experiences, especially incest or rape, can be associated
with subsequent sexual difficulties.
Performance Anxiety
Obsessive concern with adequate sexual performance is one of the most
common reasons for persistence of sexual dysfunction. "Performance
anxiety" is related to an excessive need to perform or to satisfy
the partner, with little heed paid to the individual's own pleasure
and satisfaction.
Negative Emotions
Psychological reasons for impotence include negative emotions
toward sexuality, such as anxiety, guilt, anger, or disgust. These condi-
tions may produce a so-called adrenergic response, anxiety arising from
psychological conflicts, and cause an imbalance of the autonomic nerve
functions. Anti-anxiety medications can also be impediments to sexual
performance.
| Table
1. Review of Acupuncture Points Recommended for Impotence |
| Acupuncture
Point |
Location |
Anatomy |
Physiological
Action |
Condition
Treated* |
| CV
1 |
Midpoint
between anus and scrotum (male) or posterior labial commissure (female) |
Perineal
nerve |
Enhances
sexual muscle function |
ED,
RE, OF |
| CV
2 |
Midpoint
of superior margin
of symphysis pubis |
Dorsal
blood vessels and nerves of penis,
iliohypogastric nerve |
Enhances
penile circulatory and neural control |
ED |
| CV
3 |
Midline
of abdomen, 4 cun below CV 8 |
Inferior
hypogastric plexus |
Enhances
peripheral autonomic neural control (mainly parasympathetic) |
ED |
| CV
4 |
Midline
of abdomen, 3 cun below CV 8 |
Inferior
hypogastric plexus |
Enhances
peripheral autonomic neural control (mainly parasympathetic) |
ED |
| CV
6 |
Midline
of abdomen, 1.5 cun below CV 8 |
Bifurcation
of abdominal aorta |
Increases
blood flow to the penis |
ED |
| GV
1 |
Midpoint
between coccyx and anus |
Coccygeal
nerve, hemorrhoid nerve, coccygeal
sympathetic ganglion |
Enhances
sexual muscle function, major autonomic neural
control |
ED,
PE, RE,
OF |
| GV
4 |
Midpoint
between L2 and L3 spinal
processes |
Medial
branch of posterior primary
ramus |
Major
spinal sympathetic control |
PE,
RE, OF |
| GV
16 |
Midline
of spine between C1 posterior tubercle
and occipital bone |
External
surface of medulla oblongata |
Stimulates
the medulla oblongata |
LL,
ED, PE, RE,
OF |
| GV
20 |
On
the midline of head ,midpoint of the line connecting
the apexes of the two auricles |
External
surface of cortex and hypothalamus |
Major
central neural control |
LL,
ED, PE, RE,
OF |
| BL
15 |
1.5
cun from midline of spine between T5 and T6 |
Thoracic
sympathetic ganglion |
Impulse
entering cardiac and pulmonary plexus |
ED,
PE |
| BL
18 |
1.5
cun from midline of spine between T9 and
T10 |
Thoracic
sympathetic ganglion |
Stimulates
sympathetic ganglia and ciliac ganglion, increases
arterial blood flow, stimulates adrenal cortex,
and releases testosterone |
LL,
ED, PE, RE,
OF |
| BL
19 |
1.5
cun from midline of spine between T10
and T11 |
Thoracic
sympathetic ganglion |
|
LL,
ED,PE, RE,
OF |
| BL
23 |
1.5
cun from midline of spine between L2 and L3 |
Lumbar
sympathetic ganglion |
|
LL,
ED,PE, RE, OF |
| BL
28 |
1.5
cun from midline of spine at level of S2
sacral foramen |
S2
Sacral nerve to pelvic nerve (nervus
erigentes) |
Stimulates
penile erection via pelvic nerve and inferior
hypogastric ganglion |
ED,
OF |
| BL
32 |
1
cun from midline of spine at S2 sacral
foramen |
S2
Sacral nerve to pelvic nerve
(nervus erigentes) |
Stimulates
penile erection via pelvic nerve and inferior
hypogastric ganglion |
ED,
OF |
| SP
6 |
3
cun superior to tip of medial malleolus on
posterior border of tibia |
Tibial
nerve |
Acts
on afferent impulses to sacral cord segments and inferior
hypogastric plexus (parasympathetic) |
ED,
OF |
| KI
1 |
On
sole of foot between 2nd and 3rd metatarsal
bones, proximal to metatarsal joint |
Stimulates
superficial and deep arterial
arches of the foot |
Afferent
stimulation via sympathetic nerves to midbrain
and hypothalamus |
PE,
RE, OF |
| KI
3 |
In
depression between medial malleolus
and Achilles tendon |
Tibial
nerve |
Acts
on afferent impulses to sacral cord segments and inferior
hypogastric plexus (parasympathetic) |
ED,
OF |
| HT
7 |
On
volar wrist crease on radial side of
flexor carpi ulnaris |
Ulnar
nerve |
Acts
on afferent impulses to thoracic cord segments and
cardiac and pulmonary plexus |
ED,
OF |
| PC
6 |
2
cun proximal to volar wrist crease between
tendons of palmary longus |
Medial
nerve |
Acts
on afferent impulses to thoracic cord segments and
cardiac and pulmonary plexus |
ED,
OF |
| ST
30 |
5
cun below umbilicus, 2 cun lateral to
CV 2 |
Ilio-inguinal
nerve |
Acts
on afferent tactile stimulation to sexual skin areas
(root of penis and scrotum) |
LL,
ED |
| *ED
indicates erectile dysfunction; RE, retarded ejaculation; OF, orgasmic
failure; PE, premature ejaculation; LL, loss of libido. |
Depression
Depression can be a cause of sexual impotence. The medications used
to treat depression may also produce potency problems. The tricyclic
antidepressants, monoamine oxidase inhibitors, and selective serotonin
reuptake inhibitors can cause loss of libido, retard ejaculation, and
cause orgasmic failure.
SILDENAFIL FOR MALE IMPOTENCE
Many men have been freed from worry about sexual performance due to
the discovery of sildenafil citrate.6-13 (Sildenafil was approved by
the US Food and Drug Administration March 1998, and in Canada, April
1999). The use of sildenafil has extended to many countries in Asia
and Europe.
During normal penile erection, nitric oxide is released in the endothelial
cells of the corpora cavernosa. Nitric oxide then stimulates the formation
of cyclic guanosine monophosphate (cGMP) with guanylate cyclase. As
a result, the smooth muscles are relaxed which leads to penile erection
as blood rushes into the cavernous spaces. Sildenafil is a selective
inhibitor of the naturally occurring enzyme phosphodiesterase type 5,
which causes an erection to subside after orgasm.12 Therefore, sildenafil
would be expected to restore the natural erectile response to sexual
stimulation and is used to treat erectile dysfunction.
Sildenafil is fairly effective for male erectile dysfunction.11 However,
it is not effective for loss of libido, ejaculatory dysfunction, or
orgasmic failure. Reportedly, adverse effects from sildenafil include:
o Headaches. In clinical trials, approximately 10% of men developed
severe headaches.10
o Vision Problems. Approximately 3% of men in clinical trials developed
temporary vision problems ranging from blurred vision to blue or green
hollow effects.14
o Vasosyncope. A man who takes sildenafil in combination with nitroglycerin
or other anti-hypertensive drugs could develop vasosyncope, resulting
in shock.
o Priapism. Theoretically, certain men with sickle cell anemia, leukemia,
or urethral inflammation could develop priapism, which may lead to penile
tissue damage.
o Coital Coronaries. Taking sildenafil could mask cardiac disease; impotence
is sometimes an early indicator for cardiac disease. Some patients with
cardiac disease may die from excessive sexual strain.
ACUPUNCTURE FOR MALE IMPOTENCE
For thousands of years in China, the practice of polygamy compelled
emperors of Chinese dynasties to explore sexual therapies, including
herbal medicine and acupuncture. (Each emperor routinely had 3,000 wives.)
During the 16th and early 17th centuries, sexology treatises were written
by Taoists concerning mystical sexual alchemy. These treatises include
approaches such as acupuncture and moxibustion. It was documented that
the acupuncture point nearest the Cinnabar field (CV 6) could be the
first acupuncture point for treating male sexual impotence.15 Chinese
physicians and acupuncturists have considered the Cinnabar field of
supreme significance in their respective domains. In the later centuries,
sexual therapy with acupuncture was further developed. Nevertheless,
the Chinese believed that the kidneys were responsible for sexual function.
Anyone with sexual dysfunction was labeled as having "kidney failure."
The author has conducted an informal review of the acupuncture points
recommended to treat male sexual impotence in many acupuncture texts,
and has studied and practiced these points. My conclusion is that certain
points are effective for specific sexual dysfunctions. The following
(Table 1) attempts to appreciate their efficacy by analyzing
the individual anatomical and physiological relationships.
DISCUSSION
Chinese research of acupuncture has reported that acupuncture influences
the activities of norepinephrine, acetylcholine, and their biological
enzymes in the central nervous system.16-20 During acupuncture, both
synthesis and use of central norepinephrine are accelerated. As the
rate of use exceeds that of synthesis, norepinephrine content decreases.
The effect of acupuncture is correlated intimately with the alteration
of the acetylcholine level in the brain. With appropriate acupuncture
points, acupuncture may activate the nitric oxide-cGMP pathway21,22
resulting in increase of concentration of cGMP in the corpora
cavernosa. The synergistic effect of cGMP and acupuncture might be facilitated
by endogenous acetylcholine. Needling acupuncture point GV 20 increased
cGMP in the plasma of healthy rabbits.22
Experimental results23 have shown that needling acupuncture point LI
4 at low frequency (4 Hz) may release endorphins, and high requency
(200 Hz) may release serotonin. In animal studies, it was found that
these changes in neurotransmitters affect the animals' sexual performance.23
According to some studies in rats, increase of endorphin may suppress
copulatory behavior, and decrease of endorphin may increase mounting
and intromission latencies. Naloxone induces successful copulatory behavior
in sexually inactive rats.23
Careful selection of acupuncture points and stimulus variables24 that
manipulate different neurotransmitters and peptides could be the key
to success in using acupuncture for sexual impotence.
CONCLUSION
While sildenafil is reported to be highly effective, its efficacy is
confined to penile erection and it can produce adverse effects. Acupuncture
treats not only the sexual dysfunction symptoms, but also some of the
physical and psychological causes. In addition to these advantages,
acupuncture has been found to have no known side effects.24 However,
acupuncture for male sexual impotence has not been widely practiced
and has been underrated. Its efficacy in male sexual impotence deserves
further study.
REFERENCES
1. Argiolas A, et al. Neuromodulation of penile erection: an overview
of the role of neurotransmitters and neuropeptides. Prog Neurobiol.
1995;47:235-255.
2. Wang C, et al. The influence of acupuncture on the acetylcholine
level in various regions of rat brain. Presented at: National Symposia
of Acupuncture and Moxibustion and Acupuncture Anaesthesia; Beijing,
China; June 1-5, 1979.
3. Hawton K. Sex Therapy: A Practical Guide. New York, NY: Oxford University
Press; 1985.
4. Price DE, Gingell C, Gepi-Attee S, Wareham K, Yates P, Boolell M.
Sildenafil: study of a novel oral treatment for erectile dysfunction
in diabetic men. Diabet Med. 1998;15:821-825.
5. Crenshaw TL. The Alchemy of Love and Lust: How Our Sex Hormones Influence
Our Relationships. New York, NY: Pocket Books; 1997.
6. Vaughan SC. Viagra, A Guide to the Phenomenal Potency-Promoting Drug.
New York, NY: Pocket Books; 1998.
7. Derry F, Gardner BP, Glass C, et al. Sildenafil (Viagra): a double-blind,
placebo-controlled, single-dose, two-way crossover study in men with
erectile dysfunction caused by traumatic spinal cord injury [abstract
702]. J Urol. 1997;157(suppl):181.
8. Wagner G, Montorsi F, Auerbach S, Collins M. Sildenafil citrate (Viagra)
improves erectile function in elderly patients with erectile dysfunction.
J Gerontol A Biol Sci Med Sci. 2001;56:M113-M119.
9. Auerbach S. Sildenafil (Viagra) in the treatment of erectile dysfunction:
efficacy in elderly patients. Presented at: Annual Scientific Meeting
of the American Geriatric Society/American Federation for Aging Research;
Seattle, Wash; May 1998.
10. Gingell C, Buvat J, Jardin A, et al. Sildenafil citrate (Viagra):
an oral treatment for erectile function: 1-year, open-label, extension
studies. Int J Clin Pract Suppl. 1999;102:30-31.
11. Morales A, Gingell C, Collins M, Wicker PA, Osterloh IH. Clinical
safety of oral sildenafil citrate (Viagra) in the treatment of erectile
dysfunction. Int J Impot Res. 1998;10:69-73.
12. Goldstein I, Lue TF, Padma-Nathan H, et al. Oral sildenafil in the
treatment of erectile dysfunction. N Engl J Med. 1998;338:1397-1404.
13. Ballard SA, et al. Sildenafil, an inhibitor of phosphodiesterase
type 5, enhances nitric oxide mediated relaxation of human corpus cavernosum
[abstract]. Int J Impot Res. 1996;8:103.
14. Andersson KE, Wagner G. Physiology of penile erection. Physiol Rev.
1995;75:191-236.
15. Viagra [package insert]. New York, NY: Pfizer Inc; 1998.
16. Shanghai College of Traditional Medicine. Acupuncture: A Comprehensive
Text. Seattle, Wash: Eastland Press; 1981.
17. Xu S, et al. Effects of cholinergic and dopaminergic systems of
the caudate nucleus in acupuncture analgesia. Presented at: Second National
Symposium on Acupuncture and Moxibustion and Acupuncture Anesthesia;
Beijing, China; August 1984.
18. Qin C, et al. Effect of noradrenergic descending system on the acupuncture
analgesia. Presented at: Second National Symposium on Acupuncture and
Moxibustion and Acupuncture Anesthesia; Beijing, China; August 1984.
19. Ren M, et al. The effect of hemicholine, choline, eserine and atropine
on acupuncture analgesia in the rat. Presented at: National Symposia
of Acupuncture and Moxibustion and Acupuncture Anaesthesia; Beijing,
China; June 1-5, 1979.
20. Ai M, et al. Observations on cholinesterase activity in the brain
of eserine-pretreated rats after electro-acupuncture. Presented at:
National Symposia of Acupuncture and Moxibustion and Acupuncture Anaesthesia;
Beijing, China; June 1-5, 1979.
21. Han J, et al. The study of turnover rate of CNS norepinephrine during
acupuncture analgesia in the rat. Presented at: National Symposia of
Acupuncture and Moxibustion and Acupuncture Anaesthesia; Beijing, China;
June 1-5, 1979.
22. Lu Z, et al. The relationship between cAMP and cGMP in rat brain
and acupuncture analgesia. Presented at: Second National Symposium on
Acupuncture and Moxibustion and Acupuncture Anesthesia; Beijing, China;
August 1984.
23. Pei T, et al. An experimental observation on the content of cAMP
and cGMP in rabbit's plasma due to acupuncture by reinforcing and reducing
methods. Presented at: Second National Symposium on Acupuncture and
Moxibustion and Acupuncture Anesthesia; Beijing, China; August 1984.
24. Wong J, Cheng R. The Science of Acupuncture Therapy. Hong Kong:
Kola Mayland Co; 1984.
25. Wong J. A Manual of Neuro-Anatomical Acupuncture, Vol. I: Musculo-Skeletal
Disorders. Toronto, Ontario: Toronto Pain and Stress Clinic; 1999.
AUTHOR INFORMATION
Dr Joseph Wong is a Physiatrist practicing Medical Acupuncture, and
is the originator of neuro-anatomical acupuncture. Dr Wong has lectured
worldwide, and is the Chief Lecturer and Examiner for the Acupuncture
Foundation of Canada Institute, and the Medical Director of the Toronto
(Canada) Pain and Stress Clinic. Dr Wong's books include: Manual of
TENS, The Science of Acupuncture Therapy, and A Manual of Neuro-Anatomical
Acupuncture.
Joseph Wong, MD
312-1110 Sheppard Avenue East
Toronto, Ontario M2K 2W2 Canada
Phone: 416-512-6754
Fax: 416-512-1885
E-mail: jomacyn@interlog.com.
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