I. Sildenafil Citrate Medication
Sildenafil Citrate medication is given for Erectile Dysfunction (ED).
The benefits of Sildenafil Citrate medication are:
Erectile Dysfunction: Information
Erectile dysfunction, sometimes called "impotence," is the repeated inability to get or keep an erection firm enough for sexual intercourse. The word "impotence" may also be used to describe other problems that interfere with sexual intercourse and reproduction, such as lack of sexual desire and problems with ejaculation or orgasm. Using the term erectile dysfunction makes it clear that those other problems are not involved.
Most men experience this at some point in their lives, usually by age 40, and are not psychologically affected by it. Some men, however, experience chronic, complete erectile dysfunction (impotence), and others, partial or brief erections. Frequent erectile dysfunction can cause emotional and relationship problems, and often leads to diminished self-esteem. Erectile Dysfunction has many causes, most of which are treatable, and is not an inevitable consequence of aging.
Incidence of the disorder increases with age. Chronic Erectile Dysfunction affects about 5% of men in their 40s and 15-25% of men by the age of 65. Transient ED and inadequate erection affect as many as 50% of men between the ages of 40 and 70.
Diseases (e.g., diabetes,
kidney disease, alcoholism,
atherosclerosis) account for as many as 70% of chronic Erectile
Dysfunction cases and psychological factors (e.g.,
stress, anxiety,
depression)
may account for 10-20% of cases. Between 35 and 50% of men with
diabetes
experience ED.
Causes of Erectile Dysfunction
- Since an erection requires a precise sequence of events, ED can occur when any of the events is disrupted. The sequence includes nerve impulses in the brain, spinal column, and area around the penis, and response in muscles, fibrous tissues, veins, and arteries in and near the corpora cavernosa.
- Damage to nerves, arteries, smooth muscles,
and fibrous tissues, often as a result of disease, is the most
common cause of ED. Diseases-such as diabetes,
kidney disease, chronic
alcoholism, multiple sclerosis, atherosclerosis,
vascular disease, and neurologic disease-account for about 70
percent of ED cases. Between 35 and 50 percent
of men with diabetes
experience ED.
- Also, surgery (especially radical
prostate and bladder
surgery for cancer) can injure nerves and arteries near the
penis, causing ED. Injury to the penis,
spinal cord, prostate,
bladder,
and pelvis can lead to ED by harming nerves, smooth muscles, arteries,
and fibrous tissues of the corpora cavernosa.
- In addition, many common medicines-blood
pressure drugs, antihistamines, antidepressants,
tranquilizers, appetite suppressants, and Cimetidine (an
ulcer drug)-can produce ED as a side effect.
- Experts believe that psychological factors
such as stress, anxiety,
guilt, depression,
low self-esteem, and fear of sexual
failure cause 10 to 20 percent of ED cases.
Men with a physical cause for ED frequently experience
the same sort of psychological reactions (stress, anxiety,
guilt, depression).
- Spinal cord and brain injuries (e.g.,
paraplegia, stroke) can cause impotence when they interrupt the
transfer of nerve impulses from the brain to the penis. Other
nerve disorders, such as multiple sclerosis, Parkinson's disease,
and Alzheimer's disease, may also result in impotence.
- Trauma to the pelvic region or spinal
cord can damage veins and nerves needed for erection.
Surgery of the colon, prostate,
bladder,
or rectum may damage the nerves and blood vessels involved in
erection. Prostate
and bladder
cancer surgery often require removing tissue and nerves surrounding
a tumor, which increases the risk for impotence.
- Radical cystectomy (for bladder
cancer) and prostatectomy (for prostate
cancer) require cutting or removing nerves that control penile
blood flow. These nerves do not control sensation in the penis
and are not responsible for orgasms; only erection
is affected by these procedures.
- Radiation therapy for prostate
or bladder
cancer also can permanently damage these nerves.
- Hormone disorders account for fewer than 5% of cases of impotence. Testosterone deficiency, which occurs rarely, can result in a loss of libido (sexual desire) and loss of erection. Among other conditions, an excess of the hormone prolactin, caused by pituitary gland tumor, reduces levels of testosterone. Hormone imbalances can also result from kidney or liver disease.
- Peyronie's disease is a rare inflammatory condition that causes scarring of erectile tissue. Scarring produces curvature of the penis that can interfere with sexual function and cause painful erections.
- If the veins in the penis
cannot prevent blood from leaving the penis during erection,
erection cannot be maintained. Venous
leak can be a result of injury, disease, or damage to
the veins in the penis.
- Other possible causes are smoking, which affects blood flow in veins and arteries.
Treatment of Erectile Dysfunction: Non- Surgical
Treatment
Sex Therapy
A significant number of men develop impotence from psychological
causes that can be overcome. When a physiological cause is treated,
subsequent self-esteem problems may continue to impair normal function
and performance. Qualified therapists (e.g., sex
counselors, psychotherapists) work with couples to
reduce tension,
improve sexual communication, and create realistic
expectations for sex, all of which can improve erectile
function.
Psychological therapy may be effective in conjunction with medical
or surgical treatment. Sex
therapists emphasize the need for men and their partners
to be motivated and willing to adapt to psychological and behavioral
modifications, including those that result from medical or surgical
treatment.
Medical Treatment
Oral Medication
Oral medications used to treat
erectile dysfunction include selective enzyme inhibitors
(e.g., sildenafil
[Sildenafil Citrate], vardenafil HCl [Levitra], tadalafil
[Tadalafil])
and yohimbine (Yohimbine, Yocon).
Selective enzyme inhibitors are available by prescription
and may be taken up to once a day to treat ED.
They improve
partial erections by inhibiting the enzyme that facilitates
their reduction and increase levels of cyclic guanosine monophosphate
(cGMP, a chemical factor in metabolism), which causes the smooth
muscles of the penis to relax, enabling blood to flow into the corpora
cavernosa.
Patients taking nitrate drugs (used to treat chest pain) and those
taking alpha-blockers (used to treat high
blood pressure and benign prostatic hyperplasia) should not
take selective enzyme inhibitors.
Men who have had a heart
attack or stroke
within the past 6 months and those with certain medical conditions
(e.g., uncontrolled high blood
pressure, severe low blood
pressure or liver disease, unstable angina) that make
sexual activity inadvisable should not take
Tadalafil. Dosages of the drug should be limited in patients with
kidney or liver disorders.
Sildenafil
Citrate is absorbed and processed rapidly by the body
and is usually taken 30 minutes to 1 hour before intercourse. Results
vary depending on the cause of erectile
dysfunction, but studies have shown that Sildenafil
Citrate is effective in 75% of cases. It helps men
with erectile
dysfunction associated with diabetes
mellitus (57%), spinal cord injuries (83%), and radical prostatectomy
(43%).
In clinical studies, Levitra has been shown to work quickly, provide
consistent results, and improve
sexual function in most men the first time they take
the drug. It also has shown to be effective in men of all ages,
in patients with diabetes
mellitus, and in men who have undergone radical prostatectomy.
Generic Tadalafil has been shown in clinical trials to stay in the body longer than the other selective enzyme inhibitors. Generic Tadalafil promotes erection within 30 minutes and enhances the ability to achieve erection for up to 36 hours.
Yohimbine improves erections for a small percentage of men. It stimulates the parasympathetic nervous system, which is linked to erection, and may increase libido. It is necessary to take the medication for 6 to 8 weeks before determining whether it will work or not.
Ease of administration makes oral medication advantageous. Some
drugs, however, are suitable for only a relatively small group of
men, and in many cases, oral medications may by less effective than
other treatments.
Self-Injection
Self-injection involves using a short needle to
inject medication through the side of the penis directly into the
corpus cavernosum, which produces an erection that lasts from 30
minutes to several hours. Prostaglandin (alprostadil, Caverject,
Edex), and phentolamine (Regitine) produce results similar to Generic
Sildenafil Citrate but are localized in the penis after
injection. They cause vascular dilation and a relaxation of smooth
muscle. Prostaglandin is the only substance currently approved for
erectile
dysfunction treatment. Phentolamine is a heart medicine
with similar effects used by some physicians to treat impotence.
All these drugs have been shown to produce
erections in 80% of men who inject them. Some men claim
that they produce
erections that feel natural and improve
sex. The injections are relatively painless and create
an erection that begins about 5 to 15 minutes after the injection.
It is recommended that self-injection be performed no more than
once every 4 to 7 days.
Urethral suppositories
Urethral suppositories containing prostaglandin
(aprostadil), like Muse (Medicated Urethral System
for Erections), may be an alternative to injection. Using a hand-held
delivery device, a man inserts a prostaglandin pellet through the
meatus (penis opening) into the urethra.
Prostaglandin is absorbed through the urethral
mucosa and into the surrounding erectile tissue. It is available
with a prescription, is well tolerated, and may improve
erections in 60% of men who use it.
In addition to the side effects associated with injecting aprostadil,
pain in the penis and perineum (area between scrotum and rectum)
may occur with suppository use.
Vacuum Devices
Vacuum devices work by manually creating an erection. The penis is inserted into a plastic tube, which is pressed against the body to form a seal. A hand pump attached to the tube is used to create a vacuum that draws blood into the penis, causing the penis to become engorged. After 1 to 3 minutes in the vacuum, an adequate erection is created. The penis is removed from the tube and a soft rubber O-ring is placed around the base of the penis to trap blood and maintain the erection until removed. The ring can be left in place for 25 to 30 minutes.
Vacuum devices work best in men who are able to achieve partial erections on their own. They are easy to use at home, require no other procedure, and typically improve erections regardless of the cause of impotence. Some men experience a numbing feeling after placing the O-ring. Since the penis is flaccid between the ring and the body, the erection may be somewhat floppy.
Penis: Information
The internal structure of the penis consists of two cylinder-shaped vascular tissue chambers (corpora cavernosa) that run throughout the penis (see Diagram 1). A spongy tissue fills the chambers. The spongy tissue contains smooth muscles, fibrous tissues, spaces, veins, and arteries. The Corpora cavernosa are surrounded by a membrane, called the tunica albuginea.
The urethra, which is the channel for urine and ejaculate, runs along the underside of the corpora cavernosa and is surrounded by the corpus spongiosum. The longest part of the penis is the shaft, at the end of which is the head, or glans penis. The opening at the tip of the glans, which allows for urination and ejaculation, is the meatus.
Diagram 1: Anatomy of the Penis. Explanation:
Arteries (top) and veins (bottom) penetrate the long, filled cavities
running the length of the penis-the corpora cavernosa and the corpous
sponglosum. Erection occurs when relaxed muscles allow the corpora
cavernosa to fill with excess blood fed by the arteries, while drainage
of blood through the veins is blocked.
Side effects of Anti-Impotency Drugs
Common side effects of selective enzyme inhibitors
include headache, reddening of the face and neck (flushing), indigestion,
and nasal congestion. Tadalafil
may cause muscle aches and back pain,
which usually resolve on their own within 48 hours.
Yohimbine has a stimulatory effect and side effects
include elevated heart rate and blood
pressure, mild dizziness, nervousness, and irritability.
Yohimbine's effects have not been studied thoroughly,
but some studies suggest that 10% to 20% of men respond to treatment
with the drug.
Side effects of self-injection include infection,
bleeding, and bruising at the injection site, dizziness, heart palpitations,
and flushing. There is a small risk for priapism (an erection that
lasts for more than 6 hours and requires medical relief). Repeated
injection may cause scarring of erectile tissue, which can further
impair erection.
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III. Useful links
Government http://www.cdc.gov/
http://www.fda.gov/
http://www.fda.gov/cder/ogd/
http://www.nih.gov/
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi
http://www.health.gov.on.ca/
National Library of Medicine
World Health Organization
Health Sites
http://www.medscape.com/px/urlinfo
http://www.pfizer.com/are/index.html
http://www.worldhealth.net/p/268,1847.html
http://www.mayoclinic.com/index.cfm
MedicineNet.com
Drugdigest.org
Healthsquare.com
harmacy sites
http://www.lilly.com
http://www.hsforum.com/stories/storyReader$1509 ,
http://www.hsforum.com/stories/storyReader$1516
http://www.hsforum.com/stories/storyReader$1504,
http://www.people.vcu.edu/~urdesai/atc.htm#Process%20of%20clotting
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