, also known as '''impotence''', and sometimes referred to by the less popular pop-culture term "daremonsta," is a
Sexual Dysfunction characterized by the inability to develop or maintain an
Erection of the
Penis for satisfactory
Sexual Intercourse regardless of the capability of
Ejaculation . There are various underlying causes, such as
Diabetes , many of which are medically reversible.
Due to its personal nature, the subject has been
Taboo for a long time, and is the stuff of many
Urban Legend s. Since the
1930s , folk remedies have been advertised widely for the condition. The introduction of
Sildenafil (Viagra®) in the
1990s caused 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.
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
Cardiovascular in origin. Other things leading to erectile dysfunction are
Diabetes Mellitus (causing
Neuropathy ) or
Hypogonadism (decreased
Testosterone levels due to disease affecting the
Testicle s or the
Pituitary Gland ).
There are no formal tests to diagnose erectile dysfunction. Some
Blood Test s are generally done to exclude underlying disease, such as
Diabetes ,
Hypogonadism and
Prolactinoma .
;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.
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 System of the
Brain . In both conditions an intact neural system is required for a successful and complete erection. Stimulation of penile shaft by the
Nervous System leads 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 Gland are 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
Antihypertensive s (medications intended to control
High Blood Pressure ) and some drugs that modify
Central Nervous System response 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 Circumcision may result in an increased risk of impotence,
[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14979200&dopt=Abstract while others have found no such effect,
[http://www.circs.org/library/collins/ and another found the opposite. [http://www.circs.org/library/laumann/
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
PDE5 Inhibitor s
Sildenafil (Viagra®),
Vardenafil (Levitra®) and
Tadalafil (Cialis®) are prescription drugs which are taken orally. They work by blocking the action of
PDE5 , which causes
CGMP to degrade.
CGMP causes the smooth muscle of the arteries in the penis to relax, allowing the
Corpus Cavernosum to fill with blood.
;Bremelanotide:The experimental drug
Bremelanotide (formerly PT-141) does 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. Bremelanotide works by activating
Melanocortin Receptor s in the brain. It is awaiting FDA approval.
;Ginseng:A article 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
Ohio and the defendant in class-action lawsuits.
:Enzyte is a supplement that claims to increase the male
Libido or frequency of erections of the
Penis . 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
Phallic imagery, e.g.
Golf clubs, 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 Interest have urged the
Federal Trade Commission to disallow further television
Advertising for Enzyte due to a lack of proper studies supporting claims. Enzyte maker Berkeley Premium Nutraceuticals, Inc., is currently under a
Class Action Lawsuit for
False Advertising .
:Enzyte is said to contain: ''
Tribulus Terrestris ''; Yohimbe Extract;
Niacin ;
Epimedium ; ''
Avena Sativa ''; Zinc Oxide; Maca; Muira Pauma; ''
Ginkgo biloba''; L-
Arginine ;
Saw Palmetto . Other ingredients: gelatin, rice bran, oat fiber, magnesium stearate, silicon dioxide.
Dr.
John R. Brinkley began 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.
Inn the
1930s the
American radio airwaves were bombarded with such advertising, first from domestic stations and then upon action by the
American Medical Association the media blitz was shifted to superpower
Mexican Border-blasters .
Surgeons began providing inflatable
Penile Implant s in the
1970s .
Modern drug therapy for ED was advanced enormously in 1983 when British physiologist Giles Brindley, Ph.D. dropped his trousers and demonstrated to a shocked American Urological Association audience his phentolamine-induced erection. The drug Brindley injected into his penis was a non-specific vasodilator, an alpha-blocking agent, and the mechanism of action was clearly corporal smooth muscle relaxation. The effect that Brindley discovered, established the fundamentals for the later development of specific, safe, orally-effective drug therapies.
{Link without Title}
- 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.
- Brindley GS. ''Cavernosal alpha-blocking: a new technique for investigating and treating erectile impotence.'' Br J Psychiatry. 1983 Oct;143:332-337
Abstract .
