Impotence

Encyclopedia of Alternative Medicine, Apr 06, 2001 by Ken R. Wells

Impotence, also known as erectile dysfunction, is the inability to achieve or maintain an erection long enough to engage in sexual intercourse.

Under normal circumstances, when a man is sexually stimulated, his brain sends a message down the spinal cord and into the nerves of the penis. The nerve endings in the penis release chemical messengers, called neurotransmitters, that signal the arteries that supply blood to the corpora cavernosa (the two spongy rods of tissue that span the length of the penis) to relax and fill with blood. As they expand, the corpora cavernosa close off other veins that would normally drain blood from the penis. As the penis becomes engorged with blood, it enlarges and stiffens, causing an erection. Problems with blood vessels, nerves, or tissues of the penis can interfere with an erection.

It is estimated that up to 30 million American men frequently suffer from impotence and that it strikes up to half of all men between the ages of 40 and 70. Doctors used to think that most cases of impotence were psychological in origin, but they now recognize that, 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 or disease of the connective tissue, such as Peyronie's disease, may prevent the corpora cavernosa from completely expanding. Damage to the nerves of the penis from certain types of surgery or neurological conditions, such as Parkinson's disease or multiple sclerosis , may also cause impotence. Men with diabetes are especially at risk for impotence because 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 before intercourse), 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 some cases, low levels of the male hormone testosterone may contribute to erectile failure. Finally, psychological factors, such as stress, guilt, or anxiety, may also play a role, even when the impotence is primarily due to organic causes.

When diagnosing the underlying cause of impotence, the doctor begins by asking the man a number of questions about when the problem began, whether it only happens with specific sex partners, and whether he ever wakes up with an erection. (Men whose dysfunction occurs only with certain partners or who wake up with erections are more likely to have a psychological cause for their impotence.) Sometimes, the man's sex partner is also interviewed. In some cases, domestic discord may 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 genital examination, hormone tests, and a glucose test for diabetes. Sometimes a measurement of blood flow through the penis may be taken.

Alternative health practitioners often forgo such extensive testing and rely on information obtained from the patient. Usually the fact that the man cannot get or maintain an erection is reason enough to begin alternative or holistic therapy.

A number of herbs have been promoted for treating impotence. The most widely touted is yohimbe (Corynanthe yohimbe), derived from the bark of the yohimbe tree native to West Africa. It has been used in Europe for about 75 years to treat erectile dysfunction. The FDA approved yohimbe as a treatment for impotence in the late 1980s. It is sold as an over-the-counter dietary supplement 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 impotence. It is generally believed that yohimbe dilates blood vessels and stimulates blood flow to the penis, causing an erection. It also prevents blood from flowing out of the penis during an erection. It may also act on the central nervous system, specifically the lower spinal cord area where sexual signals are transmitted. Studies show it is effective in 30-40% of men with impotence. It is primarily effective in men with impotence caused by vascular, psychogenic (originating in the mind), or diabetic problems. It usually does not work in men whose impotence is caused by organic nerve damage. In healthy men without impotence, yohimbe in some cases appears to increase sexual stamina and prolong erections.

The usual dosage of yohimbine (yohimbe extract) to treat erectile dysfunction is 5.4 mg three times a day. It may take three to six weeks for it to take effect.

Gingko (Gingko biloba), is also used to treat impotence, although it has not been conclusively shown to help the condition in controlled studies. In addition, gingko carries some risk of abnormal blood clotting and should be avoided by men taking blood thinners, such as coumadin. Other herbs promoted for treating impotence include true unicorn root (Aletrius farinosa), saw palmetto (Serenoa repens), ginseng (Panax ginseng), and Siberian ginseng (Eleuthrococcus senticosus). Nux vomica (Strychnos nux-vomica) has been recommended, especially when impotence is caused by excessive alcohol, cigarettes, or dietary indiscretions. Nux vomica can be very toxic if taken improperly, so it should be used only under the strict supervision of a physician trained in its use.