Impotence
Course AuthorsJohn E. Morley, M.D. During the last three years, Dr. Morley has received grant/research support from Vivus, Merck & Co., Upjohn, B. Braun McGaw, Bayer Corp and Nestec, Ltd. He has also served on the Speakers' Bureau for LXN, Organon, Ross, Pharmacia & Upjohn, Glaxo Wellcome, Hoechst Marion Roussel, Searle, Merck & Co., Roche, Bristol-Myers Squibb, Novartis, Pratt, B. Braun McGaw, Pfizer and Parke-Davis. This presentation will include discussion of commercial products and services. Estimated course time: 1 hour(s). Albert Einstein College of Medicine – Montefiore Medical Center designates this enduring material activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity. In support of improving patient care, this activity has been planned and implemented by Albert Einstein College of Medicine-Montefiore Medical Center and InterMDnet. Albert Einstein College of Medicine – Montefiore Medical Center is jointly accredited by the Accreditation Council for Continuing Medical Education (ACCME), the Accreditation Council for Pharmacy Education (ACPE), and the American Nurses Credentialing Center (ANCC), to provide continuing education for the healthcare team.  
Learning Objectives
Upon completion of this Cyberounds®, you should be able to:
 
Impotence (or the more politically correct term, erectile dysfunction) is defined as the inability to obtain an erection adequate for intercourse on two-thirds of the attempts. Impotence is a common, treatable condition of older males and it can be useful to let patients know this, since bringing up the issue can encourage elderly male patients who might otherwise be reluctant to mention their concern. Most of the treatments can be -- and are -- carried out by primary care physicians. Physiology of an ErectionPenile erections occur when the smooth muscle of the corpora cavernosa relaxes, resulting in blood entering the penis. Nitric oxide is the major smooth muscle dilatory neurotransmitter involved in producing a penile erection (See Figure 1). Figure 1. Impotence Is a Common Conditionp>It is estimated that impotence occurs in 10 to 20 million persons in the U.S.A.(1) Impotence occurs in one-third of persons over 40 years of age who are seeing a physician for another medical condition.(2) The Massachusetts Male Aging Study(3) reported that the combined rate of minimal, moderate and complete impotence in males 40 to 70 years was 52%. Age, vascular disease, medications, diabetes and depression were the strongest variables associated with impotence.The Impotence Top 10 List
Causes of ImpotenceIn one study 86% of all impotence was demonstrated to be organic.(2) The most common cause of impotence is vascular disease.(4) The vascular disease can be either arterial or venous. The frequency of venous leaks, resulting in the inability to maintain an erection adequate for intercourse, increase with aging. Aging is also associated with decreased penile oxygenation, leading to increased smooth muscle fibrosis. Tobacco smoking is associated with an increased incidence of impotence.(5) Smoking two cigarettes is sufficient to prevent an erection obtained by intracorporeal injection of papaverine.(6) Nicotine infusion prevents carvenoscal nerve stimulated erections in dogs. Other drugs that are associated with impotence include alcohol and heroin. Autonomic neuropathy, due to diabetes or other causes, can result in impotence. Diabetes also causes impotence by accelerating vascular disease. Because of sensory neuropathy, it is difficult to maintain adequate erections after vaginal penetration. Persons who have a sensory neuropathy-associated impotence exhibit delayed penile evoked potentials (an electric shock to the penis is perceived only after a delay in the cerebral cortex). Multiple sclerosis patients can present with "stuttering" impotence, i.e., impotence that is present for a few weeks, then goes away, only to return again. Over half of males with multiple sclerosis have impotence as their first presenting symptom. Medications are a common cause of impotence. Worldwide, thiazide diuretics are the most common medication causing impotence. Table 1. Drugs Associated with Impotence
Other Organic Causes of ImpotenceThyroid disease (both hypo- and hyper-thyroidism) causes impotence. Hyperprolactinemia also causes impotence. Decreased testosterone is more commonly associated with decreased libido than with impotence. Other organic causes of impotence include cerebrovascular accidents and spinal cord lesions (ischemic, traumatic, tumors and spinal stenosis). Depression is an important cause of impotence and all impotent males should be screened for depression. Other psychogenic causes of impotence include:
It should be noted that the commonly listed textbook factors purported to differentiate between psychogenic and organic impotence can all occur with early organic impotence. These factors are early morning erections and ability to have intercourse with a new partner but not with an old partner. Vascular Impotence Is Associated with Subsequent Major Vascular DiseaseStudies by Virag et al.(7) demonstrated a strong retrospective association of impotence withsubsequent atherosclerotic events. Our study(8) showed a prospective association between vascular impotence, as measured by penile brachial pressure index (PBPI), and future myocardial infarction or stroke: Table 2. Relationship of Penile Brachial Pressure Index (PBPI) to Vascular Disease.
All patients with vascular impotence should be referred to a cardiologist for possible stress testing. All these patients should be counseled on appropriate atherosclerotic prevention techniques, i.e., stop smoking, treat hypertension, lower cholesterol. Diagnosis of ImpotenceThe first step is to carry out an appropriate history and physical examination. The St. Louis University/Missouri Gateway Education Center/GRECC sexual history questionnaire developed by Fran Kaiser, M.D., can be obtained by clicking here. Special tests that may be indicated for the diagnosis of impotence may include:
Figure 2. Intracorporeal injections to observe erectile capacity Duplex doppler to carefully define arterial and venous blood flow. As specific treatments for vascular leakage do not exist at present this is an expensive test without any major benefit. Snap gauge--can be used to see if adequate erections occur during sleep. Nocturnal penile tumescence -- a research tool of questionable clinical use. Management of Impotence
Figure 3. Figure 4. Figure 5. Male impotence, particularly among older men, is a more common problem than most would think or, perhaps, like to think. It is most often successfully treated. Treatment can greatly improve the quality of life of elderly men (and women!) Your professional questions regarding impotence can actually be helpful, not "nosy" or improper. One of the best ways to broach what may for some be a delicate subject is to remark on just how common the problem is and take it from there. Finally, it should be remembered that older persons may indulge in high risk sex practices just as young persons do. Thus, it is important to provide them with information concerning safe sex practices, including the use of condoms. |