Barry D. Weiss, MD, College of Medicine, University of Arizona
|TIPS FOR DIAGNOSING AND TREATING ERECTILE DYSFUNCTION (ED)
Erectile dysfunction (ED) is the inability to have or maintain an erection sufficient for sexual intercourse. While uncommon in young men, ED becomes more frequent with increasing age. At age 50, only about 5% of healthy men report ED. By age 70, ED is reported in 25% of healthy men, and at age 80 the rate is over 60%. While the prevalence and severity of ED increases with age, sexual desire often remains unchanged. ED is a source of stress for many older adult men and can have negative effects on mood, depression, and overall quality of life. Despite the high prevalence, it often goes unrecognized. Studies show more than half of men do not discuss ED with their health care provider, and an even higher percentage do not receive treatment. The health care provider's role in facilitating this conversation is crucial.
Considerably higher rates of ED are found in men with neurological and vascular problems. ED is most commonly traced to one of five etiologies: medication-related, neurological, vascular, hormonal, or psychological (Table 1). Many medications have been linked to ED, and drug side-effects are thought to be responsible for up to 20% of cases. Nerve damage from diabetes mellitus can cause ED, as can local damage to the pudendal nerve that sometimes occurs with chronic pressure from activities such as long-distance bicycle riding. Decreased arterial flow from vascular illness can also lead to ED, as can hormonal imbalance, and an array of psychological issues including anxiety, stress, depression, mental illness, or dementia.
Table 1. Main Causes of Erectile Dysfunction
History A thorough medical, sexual, and psychosocial history should be performed, aimed at identifying any modifiable risk factors. These include cardiovascular disease, diabetes, hypertension, hypothyroidism, cigarette smoking, alcohol, obesity, sedentary lifestyle. Medication lists should be reviewed and updated, as ED can often be related to medication side effects (Table 2). Loss of libido can suggest either androgen deficiency or a psychological cause. Asking about nocturnal erections provides important information. The ability to develop a nocturnal erection suggests that the neurovascular function is intact and that the inability to have erections may be psychological.
Physical Examination Look for signs of vascular disease (check peripheral pulses and pedal hair), androgen deficiency (testicular atrophy or loss of secondary sex characteristics), or abnormal neurological function (poor rectal tone or an abnormal bulbocavernosus reflex). Also check for fibrous plaques in the penile shaft (Peyronie's Disease), as these may contribute to erectile dysfunction.
Blood Tests Most experts recommend measuring thyroid function tests, lipid panel, testosterone and prolactin levels. If the testosterone level is low, LH and FSH should be checked to determine if low testosterone is due to a pituitary or primary gonadal cause. If a pituitary cause is suspected (low FSH/LH levels, or high prolactin levels), neuroimaging is indicated.
Other Tests To assess for the occurrence of erections during sleep, a nocturnal penile tumescence (NPT) monitor can be used. Although testosterone-deficient men sometimes have erections during NPT monitoring, the ability to have an erection during sleep, but not with sexual arousal, suggests a psychological rather than a physical cause.
| Approach to Treatment by Etiology
Specific therapy should be directed at any modifiable risk factors, such as improved diabetic control, smoking cessation, weight loss, or changing home medications. There are also a variety of more targeted therapeutic interventions for ED which include both oral and injectable medications, and external devices. Drug-drug interactions can preclude some pharmaceutical options, however, and careful medication histories should always be obtained. Certain co-morbidities may also affect medication choice. If drug therapy is contraindicated, external devices are available.
Phosphodiesterase Type 5(PDE-5) Inhibitors are recommended as first-line therapy, and include sildenafil, vardenafil, tadalafil, and avanafil. All are equally effective, but tadalafil has a longer duration of action. PDE-5 inhibitors successfully treat more than 50% of ED. They are contraindicated in patients taking nitrates, as the combination can lead to severe hypotension. They should be avoided in men with hypotension, recent myocardial infarction, or active coronary ischemia. They are considered safe for men with stable coronary disease not on nitrates. Ischemic optic neuropathy can occur rarely with PDE-5 inhibitors, and many experts recommend that patients with retinal disorders avoid these drugs. Finally, PDE-5 inhibitors have many drug-drug interactions, so always remember to review current medication lists.
Alprostadil (prostaglandin E1), a synthetic vasodilator, can be self-injected into the corpus cavernosa of the penis or inserted as a transurethral suppository. Success rates are good, exceeding 80% in some studies. But, because oral PDE-5 inhibitors are so much easier to use, alprostadil is recommended as second-line therapy. The main risk of this treatment is priapism, which occurs in about 5% of patients.
Vacuum Devices create suction that engorges blood into the penis, thereby creating an erection. The patient operates the device manually. Blood is held in the penis with a constricting band at the base of the penis; the band should generally be removed within 30 minutes to avoid complications such as skin necrosis and is, of course, removed after intercourse. These devices have success rates of 80-90%.
Surgical implantation of a penile prosthesis can be considered in men with ED who have either failed, or declined to try, pharmacologic therapy or vacuum devices.
|Table 2. Common Substances Associated with Erectile Dysfunction
Asking About Erectile Dysfunction
Because erectile dysfunction is so common, it is important to include in the review of systems for all older adult men. For patients who are sexually active and have risk factors for ED, you can say: "Many men with [your medical problem] experience problems getting erections. Has this happened to you?" Another approach is to simply ask as part of a routine history "Are you sexually active?" - and if you get a yes, ask, "Have you or your partner experienced any sexual problems?" It is also important to learn about the various cultures of your patient population, in order to successfully approach this sensitive topic.
References and Resources
- Bacon CG, Mittleman MA, Kawachi I, Giovannucci E, Glasser DB, Rimm EB. Sexual function in men older than 50 years of age: results from the health professionals follow-up study. Ann Intern Med. 2003;139(3):161-168.
- Lue TF. Erectile dysfunction. N Engl J Med. 2000;342(24):1802-1813.
- Miller TA. Diagnostic evaluation of erectile dysfunction. Am Fam Physician. 2000;61(1):95-104, 109-10.
- Mola JR. Erectile Dysfunction in the Older Adult Male. Urol Nurs. 2015 Mar-Apr;35(2):87-93.