Erectile dysfunction

Erectile dysfunction,Or also known as impotence Or , is a sexual dysfunctioncharacterized by the inability to develop or maintain an erectionof the penisfor satisfactory sexual intercourseregardless of the capability of ejaculation. There are various underlying causes, including Type 1 diabetes, many of which are medically reversible.

Due to its personal nature, the subject has been taboofor a long time, and is the stuff of many urban legends. Since the 1930s, folk remedies have been advertised widely for the condition. The introduction of sildenafil(Viagra®) in the 1990scaused a second wave of public attention, propelled in part by heavy advertising.

The Latin term impotentia coeundi describes simple inability to insert the penis into the vagina. It is now mostly replaced by more precise terms.

Medical symptoms

Erectile dysfunction is characterized by the inability to maintain erection. Normal erections during sleep and in the early morning suggest a psychogenic cause, while loss of these erections may signify underlying disease, often cardiovascularin origin. Other things leading to erectile dysfunction are diabetes mellitus(causing neuropathy) or hypogonadism(decreased testosteronelevels due to disease affecting the testiclesor the pituitary gland).

Medical diagnosis

There are no formal tests to diagnose erectile dysfunction. Some blood testsare generally done to exclude underlying disease, such as diabetes, hypogonadismand prolactinoma.

Clinical tests used to diagnose ED

Duplex ultrasound

Duplex ultrasound is used to evaluate blood flow, venous leak, signs of atherosclerosis, and scarring or calcification of erectile tissue. Injecting prostaglandin, a hormone-like stimulator produced in the body, induces erection. Ultrasound is then used to see vascular dilation and measure penile blood pressure. Measurements are compared to those taken when the penis is flaccid.

Penile nerves function

Tests such as the bulbocavernosus reflex test are used to determine if there is sufficient nerve sensation in the penis. The physician squeezes the glans (head) of the penis, which immediately causes the anus to contract if nerve function is normal. A physician measures the latency between squeeze and contraction by observing the anal sphincter or by feeling it with a gloved finger inserted past the anus. Specific nerve tests are used in patients with suspected nerve damage as a result of diabetes or nerve disease.

Nocturnal penile tumescence (NPT)

It is normal for a man to have five to six erections during sleep, especially during rapid eye movement (REM). Their absence may indicate a problem with nerve function or blood supply in the penis. There are two methods for measuring changes in penile rigidity and circumference during nocturnal erection: snap gauge and strain gauge.

Penile biothesiometry

This test uses electromagnetic vibration to evaluate sensitivity and nerve function in the glans and shaft of the penis. A decreased perception of vibration may indicate nerve damage in the pelvic area, which can lead to impotence.

Pathophysiology

Penile erection is managed by two different mechanisms. The first one is the reflex erection, which is achieved by directly touching the penile shaft. The second is the psychogenic erection, which is achieved by erotic stimuli. The former uses the peripheral nerves and the lower parts of the spinal cord, whereas the latter uses the limbic systemof the brain. In both conditions an intact neural system is required for a successful and complete erection. Stimulation of penile shaft by the nervous systemleads to the secretion of nitric oxide(NO), which causes the relaxation of smooth muscles of corpora cavernosa (the main erectile tissue of penis), and subsequently penile erection. Additionally, adequate levels of testosterone(produced by the testes) and an intact pituitary glandare required for the development of a healthy male erectile system. As can be understood from the mechanisms of a normal erection, impotence may develop due to hormonal deficiency, disorders of the neural system, lack of adequate penile blood supply or psychological problems.

A few causes of impotence may be iatrogenic(medically caused). Various antihypertensives(medications intended to control high blood pressure) and some drugs that modify central nervous systemresponse may inhibit erection by denying blood supply or by altering nerve activity. Antidepressants, especially SSRIs, can cause impotence as a side effect. Surgical intervention for a number of different conditions may remove anatomical structures necessary to erection, damage nerves, or impair blood supply. Some studies have shown that male circumcisionmay result in an increased risk of impotence, [1][2]while others have found no such effect, [3][4][5], and another found the opposite. [6]

Treatment

Treatment depends on the cause. Testosterone supplements may be used for cases with hormonal deficiency. However, usually the cause is lack of adequate penile blood supply as a result of age-dependent damage of inner walls of blood vessels. Previously, medical substances (e.g. apomorphine) were directly injected into the erectile tissue of penile shaft to treat impotence. In some cases refractory to the medical treatment, a penile implant (penile prosthesis) could be advised. After the discovery of orally active agents that increase the efficacy of NO, which dilates the blood vessels of corpora cavernosa, more conservative methods started to be used.

PDE5 Inhibitors

The prescription PDE5inhibitors sildenafil(Viagra®), vardenafil(Levitra®) and tadalafil(Cialis®) are prescription drugs which are taken orally. They work by blocking the action of PDE5, which causes cGMPto degrade. cGMPcauses the smooth muscle of the arteries in the penis to relax, allowing the corpus cavernosumto fill with blood.

PT-141

The experimental drug PT-141does not act on the vascular system like the former compounds but increases sexual desire and drive in male as well as female. It is applied as a nasal spray PT-141 and works by activation of melanocortinreceptorsin the brain. It is awaiting FDA approval.

Ginseng

A double-blindstudy appears to show evidence that ginsengis better than placebo: see the ginsengarticle for links and more details.

Enzyte

Enzyte is a product that has been advertised by saturation coverage on television channels such as Court-TV. However, the Center for Science in the Public Interest (CSPI) has filed a complaint with the Federal Trade Commission(FTC) about Enzyte for deceptive advertising. It is manufactured by Berkeley Nutritionals, which is alleged to be the subject of an investigation by the Attorney General of Ohioand the defendant in class-action lawsuits.

Enzyte is a supplement that claims to increase the frequency of erections of the male penisor libido. Commercials for Enzyte are shown regularly on television. These commercials feature a man named Bob who never stops smiling, apparently because he had taken Enzyte and improved the size of his sex organs. The commercials are riddled with symbolic phallicimagery, e.g. golfclubs, remarkably tall glasses of iced tea, and a hose spraying barely a trickle of water (carried by someone who doesn't use Enzyte).

The effectiveness of Enzyte is in dispute. Some medical professionals in fact advise against taking Enzyte, saying that it can lead to damage. The Center for Science in the Public Interesthave urged the Federal Trade Commissionto disallow further television advertisingfor Enzyte due to a lack of proper studies supporting claims. Enzyte maker Berkeley Premium Nutraceuticals, Inc., is currently under a class action lawsuitfor false advertising.

Enzyte is said to contain: Tribulus terrestris; Yohimbe Extract; Niacin; Epimedium; Avena sativa; Zinc Oxide; Maca; Muira Pauma; Ginkgobiloba; L-Arginine; Saw Palmetto. Other ingredients: gelatin, rice bran, oat fiber, magnesium stearate, silicon dioxide.

History

Dr. John R. Brinkleybegan a fad for finding cures for male impotence during the 1930s. He used the medium of radio to achieve the same kind of advertising boom to treat the same kind of symptoms.

In the 1930sthe Americanradio airwaves were bombarded with such advertising, first from domestic stations and then upon action by the American Medical Associationthe media blitz was shifted to superpower Mexicanborder-blasters.

Surgeons began providing inflatable penile implantsin the 1970s.

References

• Cheitlin MD, Hutter AM Jr, Brindis RG, Ganz P, Kaul S, Russell RO Jr, Zusman RM. ACC/AHA expert consensus document. Use of sildenafil (Viagra) in patients with cardiovascular disease. American College of Cardiology/American Heart Association. J Am Coll Cardiol. 1999 Jan;33(1):273-82. Fulltext. PMID 9935041.

External sources

• FDA's Consumer Information
• Erectile Dysfunction Primer
• Support group for people with permanent impotence or other sexual dysfunction casued by SSRI antidepressants.
• Erection WebSupport group for people with erectile dysfunction and impotence.
• Enzyte Company website
• Enzyte investigation reported on CBS-TV news siteda:Impotens

de:Erektile Dysfunktion es:Disfunción eréctil fr:Impuissance nl:Impotentie pl:Impotencja pt:Disfunção erétil zh:??

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It uses material from the http://en.wikipedia.org/wiki/Erectile+dysfunction Wikipedia article Erectile dysfunction.