Definition
Erectile dysfunction (ED), formerly known as impotence, is the inability to achieve or maintain an erection long enough toengage in sexual intercourse.
Description
Under normal circumstances, when a man is sexually stimulated, his brain sends a message down the spinal cord and intothe nerves of the penis. The nerve endings in the penis release chemical messengers, called neurotransmitters, that signalthe arteries that supply blood to the corpora cavernosa (the two spongy rods of tissue that span the length of the penis) torelax and fill with blood. As they expand, the corpora cavernosa close off other veins that would normally drain blood fromthe penis. As the penis becomes engorged with blood, it enlarges and stiffens, causing an erection. Problems with bloodvessels, nerves, or tissues of the penis can interfere with an erection.
Causes and symptoms
It is estimated that up to 30 million American men frequently suffer from ED and that it strikes up to half of all men betweenthe ages of 40 and 70. Doctors used to think that most cases of ED were psychological in origin, but they now recognizethat, at least in older men, physical causes may play a primary role in 60% or more of all cases. In men over the age of 60,the leading cause is atherosclerosis, or narrowing of the arteries, which can restrict the flow of blood to the penis. Injury ordisease of the connective tissue, such as Peyronie's disease, may prevent the corpora cavernosa from completelyexpanding. Damage to the nerves of the penis from certain types of surgery or neurological conditions, such as Parkinson'sdisease or multiple sclerosis, may also cause ED. Men with diabetes are especially at risk for erectile dysfunctionbecause of their high risk of both atherosclerosis and a nerve disease called diabetic neuropathy.
Some drugs, including certain types of blood pressure medications, antihistamines, tranquilizers (especially beforeintercourse), and antidepressants known as selective serotonin reuptake inhibitors (SSRIs, including Prozac and Paxil)can interfere with erections. Smoking, excessive alcohol consumption, and illicit drug use may also contribute. In somecases, low levels of the male hormone testosterone may contribute to erectile failure. Finally, psychological factors, suchas stress, guilt, or anxiety, may also play a role, even when the ED is primarily due to organic causes.
Diagnosis
When diagnosing the underlying cause of erectile dysfunction, the doctor begins by asking the man a number of questionsabout when the problem began, whether it only happens with specific sex partners, and whether he ever wakes up with anerection. (Men whose dysfunction occurs only with certain partners or who wake up with erections are more likely to have apsychological cause for their ED.) Sometimes, the man's sex partner is also interviewed. In some cases, domestic discordmay be a factor.
The doctor also obtains a thorough medical history to find out about past pelvic surgery, diabetes, cardiovascular disease,kidney disease, and any medications the man may be taking. The physical examination should include a genitalexamination, hormone tests, and a glucose test for diabetes. Sometimes a measurement of blood flow through the penismay be taken.
Treatment
Years ago, the standard treatment for erectile dysfunction was a penile implant or long-term psychotherapy. Althoughphysical causes are now more readily diagnosed and treated, individual or marital counseling is still an effective treatmentfor ED when emotional factors play a role.
There are three prescription medications available in the United States to treat the physical causes of ED: sildenafil citrate (Viagra), vardenafil (Levitra), and tadalafil (Cialis). They help about three-fourths of all men who try them in thegeneral population. Several studies have indicated that their success rate in diabetic men may be slightly lower, averagingaround 60-65%. All three pills work by enhancing the effects of nitric oxide. This chemical relaxes muscles in the penis toallow more blood to flow in. These pills do not cause an erection by themselves. Sexual stimulation is also required.Sildenafil or vardenafil should be taken about an hour before sex. Each is effective for roughly four hours. Tadalafil lasts forup to 36 hours. Men should not have sex more than once every 24 hours after using these drugs. Before Viagra's approval in1998, drug treatment of erectile dysfunction was limited to alprostadil (prostaglandin [E.sub.1]), either injected into the penisor inserted as a pellet into the urethra. Sales of the three newer ED drugs reached $3.4 billion in 2004, according to theresearch firm IMS Health. In 2004, Viagra had about 66% of the market share for ED drugs compared to 19% for Levitra and14% for Cialis.
Viagra
Sildenafil citrate was originally developed in 1991 as a treatment for angina, or chest pain. The drug, marketed under thename Viagra, received FDA approval as a treatment for erectile dysfunction in March 1998, and since that time it has beenprescribed for more then 20 million men worldwide. It was the first oral medication approved for ED treatment. Viagra is avasodilator, a drug that has the effect of dilating the blood vessels. It works by improving blood circulation to the penis, andby enhancing the effects of nitric oxide, the agent that relaxes the smooth muscle of the penis and regulates blood vesselsduring sexual stimulation, allowing the penis to become engorged and achieve an erection.
The average recommended dose of Viagra is 50 mg. It comes in doses of 25 mg., 50 mg., and 100 mg to. The medication istaken approximately one hour before sexual activity is planned, and may remain effective for up to four hours. One drawbackis that to be effective, it should be taken on an empty stomach. Also, high-fat foods can interfere with the absorption ofViagra. Viagra does not increase sexual desire. Sexual stimulation and arousal are required for it to be effective.
Many insurance plans cover the cost of Viagra, provided it is prescribed to treat erectile dysfunction. The pills costapproximately $10 each, and insurers may limit coverage to a specific number of pills each month.
The primary drawback to Viagra, which works about an hour after it is taken, it that the FDA cautions men with heartdisease or low blood pressure to be thoroughly examined by a physician before obtaining a prescription. At least 130 menhave died while taking Viagra. However, the FDA said the men—most over the age of 64—died of heart attack or strokedue to health problems exaggerated by sexual activity, not the drug itself.
Levitra
In early 2003, a second prescription drug to treat erectile dysfunction, Levitra, was approved by the FDA. Like Viagra,Levitra helps increase blood flow to the penis and may help men with ED get and keep an erection. Once a man hascompleted sexual activity, blood flow to the penis should decrease and the erection should go away. Levitra should be takenapproximately 60 minutes prior to sexual activity. In clinical trials, most patients were able to begin sexual activity beforethat time. A 2004 study showed that about 50% of men taking Levitra experienced a firm erection within 25 minutes and asmall percentage in as quickly as 10 minutes. Studies also showed that Levitra improved erectile function in men who hadother health factors, such as diabetes or prostate surgery.
Men taking nitrate drugs, often used to control chest pain (also known as angina), should not take Levitra. Men who usealpha-blockers, sometimes prescribed for high blood pressure or prostate problems, also should not take Levitra. Suchcombinations could cause blood pressure to drop to an unsafe level. Levitra is available in 2.5 mg, 5 mg, 10 mg, and 20 mgtablets and should be taken no more than once a day. The average cost per pill is about $10 and is covered by manyinsurance plans.
Cialis
Cialis is the third oral drug prescribed to treat erectile dysfunction, approved by the FDA in November 2003. Its most notabledifference from Viagra and Levitra, which work for about four hours, is that Cialis works for up to 36 hours. Cialis helpsincrease blood flow in the penis when a man is sexually stimulated. It can help men with ED get and keep an erectionsatisfactory for sexual activity. Once a man has completed sexual activity, blood flow to his penis decreases, and hiserection goes away. Cialis is clinically proven to improve erectile function in most men with ED, including those with mild,moderate or severe ED.
The most common side effects with Cialis are headache, upset stomach, back pain, and muscle aches. These sideeffects usually go away after a few hours. Patients who get back pain and muscle aches usually get it 12 to 24 hours aftertaking Cialis. Back pain and muscle aches usually go away by themselves within 48 hours.
Cialis comes in 5 mg., 10 mg. (the recommended starting dose), and 20 mg. tablets. The average cost per tablet is about$10 and it is covered by many insurance plans. Since the absorption of Cialis is not affected by food or high-fat foods, itdoes not need to be taken on an empty stomach. Studies show that in most men, Cialis begins working in about 30minutes and may be taken up to once per day by most patients.
Priapism, a prolonged erection, is a very rare potential side effect of all prescription ED medications. Persons takingViagra, Levitra, or Cialis who have a prolonged erection, lasting more than four hours, should seek immediate medicalattention. Priapism can cause damage to the penis potentially leading to the permanent inability to have an erection.
Because sexual activity can stress the heart, men who have heart problems should check with their physician to see ifsexual activity is recommended. Erectile dysfunction drugs may trigger temporary hypotension (low blood pressure) and isknown to increase cardiovascular nerve activity, so physicians should prescribe them with caution in men with a history ofheart attack, atherosclerosis (hardening of the arteries), angina, arrhythmia, and chronic low blood pressure problems. EDdrugs are not labeled or approved for use by women or children, or by men without erectile dysfunction. Anyoneexperiencing cardiovascular symptoms such as dizziness, chest or arm pain, and nausea when participating in sexualactivity after taking an ED medication should stop the encounter. They should also not take any ED drug again until theyhave discussed the episode with their healthcare provider. It is recommended that men with kidney or liver impairments, andmen over age 65, start at the lowest possible dosage of ED medications.
Other treatment options
Although the commercial availability of Viagra, Levitra, and Cialis has been useful in many men, prostate cancer patientsand ED caused by psychological problems often require alternative treatment. A commonly used alternative consists of athree-drug injection containing alprostadil, papaverine hydrochloride, and phentolamine mesylate. Though it is commonlyreferred to as the "Knoxville formula," apparently for the city of its original introduction, a number of slightly varying formulashave been in use around the country. The three-drug preparation is administered by injection into the corpora cavernosa toinduce erection.
Other traditional therapies for ED include vacuum pump therapy, injection therapy involving injecting a substance into thepenis to enhance blood flow, and a penile implantation device. In rare cases, if narrowed or diseased veins are responsiblefor ED, surgeons may reroute the blood flow into the corpora cavernosa or remove leaking vessels.
In vacuum pump therapy, a man inserts his penis into a clear plastic cylinder and uses a pump to force air out of thecylinder. This forms a partial vacuum around the penis, which helps to draw blood into the corpora cavernosa. The man thenplaces a special ring over the base of the penis to trap the blood inside it. The only side effect with this type of treatment isoccasional bruising if the vacuum is left on too long.
Injection therapy involves injecting a substance into the penis to enhance blood flow and cause an erection. The FDAapproved a drug called alprostadil (Caverject) for this purpose in 1995. Alprostadil relaxes smooth muscle tissue to enhanceblood flow into the penis. It must be injected shortly before intercourse. Another, similar drug that is sometimes used ispapaverine. Either drug may sometimes cause painful erections or priapism that must be treated with a shot of epinephrine.Alprostadil may also be administered into the urethral opening of the penis. In MUSE (medical urethral system for erection),the man inserts a thin tube the width of a spaghetti noodle into his urethral opening and presses down on a plunger todeliver a tiny pellet containing alprostadil into his penis. The drug takes about 10 minutes to work and the erection lastsabout an hour. The main side effect is a sensation of pain and burning in the urethra, which can last about five to 15minutes. The injection process itself is often painful
Implantable penile prostheses are usually considered a last resort for treating erectile dysfunction. They are implanted inthe corpora cavernosa to make the penis rigid without the need for blood flow. The semi-rigid type of prosthesis consists ofa pair of flexible silicone rods that can be bent up or down. This type of device has a low failure rate but, unfortunately, itcauses the penis to always be erect, which can be difficult to conceal under clothing.
The inflatable type of device consists of cylinders that are implanted in the corpora cavernosa, a fluid reservoir implanted inthe abdomen, and a pump placed in the scrotum. The man squeezes the pump to move fluid into the cylinders and causethem to become rigid. (He reverses the process by squeezing the pump again.) While these devices allow for intermittenterections, they have a slightly higher malfunction rate than the silicon rods. Men can return to sexual activity six to eightweeks after implantation surgery. Since implants affect the corpora cavernosa, they permanently take away a man's abilityto have a natural erection.
Alternative treatment
A number of herbs have been promoted for treating erectile dysfunction. The most widely touted is yohimbe (Corynantheyohimbe), derived from the bark of the yohimbe tree native to West Africa. It has been used in Europe for about 75 years totreat ED. The FDA approved yohimbe as a treatment for ED in the late 1980s. It is sold as an over-the-counter dietarysupplement and as a prescription drug under brand names such as Yocon, Aphrodyne, Erex, Yohimex, Testomar,Yohimbe, and Yovital.
There is no clear medical research that indicates exactly how or why yohimbe works in treating ED. It is generally believedthat yohimbe dilates blood vessels and stimulates blood flow to the penis, causing an erection. It also prevents blood fromflowing out of the penis during an erection. It may also act on the central nervous system, specifically the lower spinal cordarea where sexual signals are transmitted. Studies show it is effective to some degree in 30-40% of men with ED. It isprimarily effective in men with ED caused by vascular, psychogenic (originating in the mind), or diabetic problems. It usuallydoes not work in men whose dysfunction is caused by organic nerve damage. In healthy men without ED, yohimbe in somecases appears to increase sexual stamina and prolong erections. The usual dosage of yohimbine (yohimbe extract) to treatED is 5.4 mg three times a day. It may take three to six weeks for it to take effect.
Ginkgo Ginkgo biloba, is also used to treat erectile dysfunction, although it has not been shown to help the condition incontrolled studies, and probably has more of a psychological effect. In addition, ginkgo carries some risk of abnormal bloodclotting and should be avoided by men taking blood thinners, such as coumadin. Other herbs promoted for treating EDinclude true unicorn root Aletrius farinosa, saw palmetto Serenoa repens, ginseng Panax ginseng, and Siberian ginsengEleuthrococcus senticosus. Nux vomica Strychnos nux-vomica has been recommended, especially when ED is caused byexcessive alcohol, cigarettes, or dietary indiscretions. Nux vomica can be very toxic if taken improperly, so it should beused only under the strict supervision of a physician trained in its use.
There are quite a few Chinese herbal remedies for erectile dysfunction usually combinations of herbs and sometimes animalparts such as deer antler and sea horse. Acupuncture is also used to treat ED, although Western doctors question itseffectiveness.
Key terms
Antihistamines — A drug that blocks cell receptors for histamine, usually to prevent allergic effects such as sneezing anditching.
Atherosclerosis — An arterial disease in which raised areas of degeneration and cholesterol deposits (plaques) form on theinner surfaces of the arteries. Also called hardening of the arteries.
Corpora cavernosa — Either of a pair of columns of erectile tissue at either side of the penis that, together with the corpusspongiosum, produce an erection when filled with blood.
Diabetic neuropathy — A disease or disorder, especially a degenerative one, caused by diabetes that affects the nervoussystem.
Neurotransmitter — A chemical that carries messages between different nerve cells or between nerve cells and muscles.
Peyronie's disease — Local fibrous scarring causing the erect penis to be bent to such a degree that it interferes withsexual intercourse.
Vasodilator — An agent, such as a nerve or hormone, that widens the blood vessels, which in turn decreases resistanceto blood flow and lowers blood pressure.
Prognosis
With proper diagnosis, erectile dysfunction can nearly always be treated or coped with successfully. Unfortunately, fewerthan 10% of men with ED seek treatment. However, with the heavy advertising and marketing associated with Viagra,Levitra, and Cialis, this number is expected to rise dramatically.
Prevention
There is no specific treatment to prevent erectile dysfunction. Perhaps the most important measure is to maintain generalgood health and avoid atherosclerosis by exercising regularly, controlling weight, controlling hypertension and highcholesterol levels, and not smoking. Avoiding excessive alcohol intake may also help.
Resources
Books
Icon Health Publications. The Official Patient's Sourcebook on Erectile Dysfunction: A Revised and Updated Directory forthe Internet Age. San Diego: Icon Health Publications, 2005.
Kloner, Robert A. Heart Disease and Erectile Dysfunction. Totowa, NJ: Humana Press, 2004.
Lue, Tom F. An Atlas of Erectile Dysfunction, Second Edition. London: Taylor & Francis Group, 2003.
Metz, Michael E. and Barry W. McCarthy. Coping With Erectile Dysfunction: How to Regain Confidence and Enjoy GreatSex Oakland, CA: New Harbinger Publications, 2004.
Periodicals
Roberts, Shauna S. "Options Increase for Men With Erectile Dysfunction: Doctors Now Have an Array of Treatments forMen's Sexual Problems." Diabetes Forecast (September 2004): 55-58.
Sadovsky, Richard. "Sildenafil is Safe and Effective in Men With Stable CAD." American Family Physician (September 1,2004): 955.
Tomlinson, John. "The Patient With Erectile Dysfunction." The Practitioner (February 9, 2005): 104.
Trissel, Lawrence A. "Long-Term Stability of Trimix: A Three-Drug Injection Used to Treat Erectile Dysfunction." InternationalJournal of Pharmaceutical Compounding (May-June 2004): 231-235.
Wooten, James M. "Erectile Dysfunction: There are Now Three Effective Oral Drugs for Treating ED, Paving the Way forNurses to Put Patients With This Condition on the Road to Good Sexual Health." RN (October 2004): 40.
Zoler, Mitchel L. "Drug Update: Erectile Dysfunction." OB/GYN News (April 15, 2004): 92.
Organizations
Erectile Dysfunction Information Center. 10949 Bren Road East, Minnetonka, MN 55343-9613. (866) 294-7508.publisher@erectile-dysfunction-impotence.org. http://www.cure-ed.org. 952-852-5560
Other
December 2003. National Kidney and Urologic Diseases Information Clearinghouse Erectile Dysfunctionhttp://kidney.niddk.nih.gov/kudiseases/pubs/impotence/ (Accessed March 24, 2005).
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
erectile dysfunction
n. Abbr. ED
The inability to achieve penile erection or to maintain an erection until ejaculation. Also called impotence.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
erectile dysfunction.
Mosby's Medical Dictionary, 8th edition. © 2009, Elsevier.
dysfunction
[dis-fungk´shun]
disturbance, impairment, or abnormality of functioning of an organ. adj., adj dysfunc´tional.
risk for peripheral neurovascular dysfunction a nursing diagnosis accepted by the North American Nursing DiagnosisAssociation, defined as being at risk for disruption in circulation, sensation, or motion of an extremity or limb.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
erectile dysfunction
Urology A consistent inability to sustain an erection/penile tumescence sufficient forsexual intercourse Etiology Medical–eg, severe heart disease, psychologic–lack of sexual desire, defects in ejaculation andorgasm, surgical; ED affects 20–30 million ♂–US; up to 23% of impotent ♂ have ↓ testosterone Management Vacuum pumpsystem, penile injection therapy, penile implant surgery, microvascular bypass surgery. See Impotence, Penile implant. CfBlue balls.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
erectile dysfunction
inability to achieve or maintain penile tumescence sufficient for sexual intromission or for achieving orgasm.
Farlex Partner Medical Dictionary © Farlex 2012
e·rec·tile dys·func·tion
(ED) (ĕ-rek'tīl dis-fŭngk'shŭn)
Any disorder of penile erection that prevents successful performance of coitus.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
Patient discussion about erectile dysfunction
Q. I started to suffer from erectile dysfunction? Why is this happening and what can I do to treat it? I am a healthy 52year old. I have hypertension but i take pills to treat it and my levels are around 130/80. except that I am at great shape. In thelast few months I feel that a problem in my sex life. I want to have sex but i can't due to erectile dysfunction. What can be thereason for this? and more important what can I do?
A. get rize2 it lasts about 4 days,and all you have to do is think about sex
and you get a rock hard erection!!!!!
and you get a rock hard erection!!!!!
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