Am Fam Physician. 2006;73(2):340-344
The American Urological Association (AUA) has updated its 1996 recommendations on the treatment of erectile dysfunction (ED). The updated guidelines are available online at http://www.auanet.org/guidelines/edmgmt.cfm.
A typical evaluation for ED should be conducted in person and should include a thorough sexual, medical, and psychosocial history, focusing on conditions such as cardiovascular disease (e.g., hypertension, atherosclerosis, hyperlipidemia), diabetes, depression, alcoholism, premature ejaculation, increased latency associated with age, psychosexual relationships, and other conditions that might be contraindications for certain drug therapies. Other risk factors for ED that may be discovered include smoking; pelvic, perianal, or penile trauma; neurologic disease; endocrinopathy; obesity; pelvic radiation therapy; Peyronie’s disease; and prescription or illicit drug use. During the evaluation, special attention should be paid to defining the problem and clearly distinguishing ED from problems with ejaculation or orgasm, as well as establishing the chronology and severity of symptoms.
After the initial examination, a physical examination should be performed, focusing on the abdomen, penis, testicles, secondary sexual characteristics, and lower extremity pulses. A rectal examination, vascular and neurologic assessment, determination of prostate-specific antigen and testosterone levels, and monitoring of nocturnal erections may be indicated in some patients.
ED results from a combination of vascular, neurologic, hormonal, and psychologic factors. Conditions that affect the arterial or venous systems have a negative effect on erectile function. Diabetes, heart disease, and hypertension increase the risk of ED, and management of these conditions may prevent the development of ED. Minimal evidence also suggests that maintaining ideal body weight, not smoking, and exercising regularly may prevent or reverse ED.
Many patients with ED also have cardiovascular disease. High-risk patients (e.g., those with unstable or refractory angina, uncontrolled hypertension, left ventricular dysfunction or congestive heart failure, myocardial infarction [MI] or a cardiovascular event in the past two weeks, high-risk arrhythmias, cardiomyopathy, or moderate to severe valvular disease) should not receive treatment for ED until their cardiac condition has stabilized because of increased risk of MI during sexual activity.
Education, support, and reassurance may be enough to restore sexual function in some patients. In other patients, different ED therapies should be tried with increasing invasiveness. The choice of treatment should be made jointly by the physician, patient, and the patient’s partner.
The review panel considered the following nonsurgical therapies for ED: phosphodiesterase type 5 (PDE5) inhibitors, alprostadil (Caverject, Prostin VR) intraurethral suppositories, intracavernous injection, vacuum constriction devices, and herbal therapies.
The AUA recommends that PDE5 inhibitors be offered as the first-line therapy for ED unless contraindicated. The three PDE5 inhibitors studied (i.e., sildenafil [Viagra], tadalafil [Cialis], and vardenafil [Levitra]) are metabolized by the liver, and dosage should be adjusted for patients with altered hepatic function. The side effects of all three medications include facial flushing, nasal congestion, headache, and dyspepsia. Sildenafil and vardenafil may cause visual side effects. A limited number a patients taking tadalafil report back pain. Vardenafil may cause mild prolongation of QT interval; caution should be used when prescribing this agent for patients with a history of QT prolongation or those taking medications that prolong the QT interval.
Many men being treated for ED also are taking medication for treatment of hypertension or lower urinary tract symptoms. PDE5 inhibitors interact with beta blockers, a class of drugs commonly used to treat hypertension and lower urinary tract symptoms. Vardenafil should not be used by any patient taking any other medication with alpha blocker activity. Any dose of tadalafil and 50- and 100-mg doses of sildenafil should be administered with caution to patients taking alpha blockers.
Patients taking PDE5 inhibitors should not take organic nitrates concomitantly. No safe interval between the use of nitrates and PDE5 has been determined, but it is suggested that a 24-hour interval be used for sildenafil and a 48-hour interval be used for tadalafil.
It is important that physicians monitor the effectiveness, side effects, and health changes in patients using PDE5 inhibitors. This can be done at the time of prescription renewal. Patients who do not respond to PDE5 inhibitors may have modifiable risk factors such as hormonal abnormalities, food or drug interactions, incorrect dosing, lack of adequate sexual stimulation, heavy alcohol use, or relationship problems with their partner. Patients who do not respond to PDE5 inhibitors should be informed of the risks and benefits of other therapies.
ALPROSTADIL INTRAURETHRAL SUPPOSITORIES
The panel recommends that the first dose of alprostadil intraurethral suppositories be administered under a physician’s supervision because hypotension has been reported in approximately 3 percent of patients. Studies show that alprostadil combined with PDE5 inhibitors or a penile constriction device is more effective than the use of alprostadil alone.
INTRACAVERNOUS VASOACTIVE DRUG INJECTION THERAPY
Intracavernous injection therapy is invasive, but it is the most effective nonsurgical treatment for ED. The most widely used drugs for this therapy are alprostadil, papaverine (Pavabid), and phentolamine. The initial dose of all intracavernous injection medications should be administered in the presence of a physician to instruct the patient on proper technique, determine the most effective dose, and monitor the patient for side effects. It is important to watch for priapism in patients taking intracavernous injection therapy. Priapism can cause corporal tissue damage but, if caught early, usually can be reversed with nonsurgical measures.
VACUUM CONSTRICTION DEVICES
Vacuum constriction devices are a low-cost treatment appropriate for some patients with ED. To avoid injury to the penis, only devices that contain a vacuum limiter should be used. Vacuum constriction devices are available with or without a prescription.
Topical therapies for the treatment of ED are not currently approved by the U.S. Food and Drug Administration. Limited studies show that topical application of vasoactive drugs does not appear to be significantly more effective than intraurethral alprostadil.
TREATMENTS NOT RECOMMENDED BY THE AUA
Trazodone (Desyrel), testosterone (in patients with normal serum testosterone levels), and yohimbine and other herbal therapies are not recommended for treatment of ED.
Penile Prosthesis Implantation
The panel limited its discussion to inflatable penile prostheses. Patients considering prosthesis should be informed of the types of prostheses available, possible side effects, differences between the pre- and postprosthetic penis, and the potential reduction in effectiveness of other ED treatments if the device is removed.
Inflatable penile prostheses can result in complications such as pump displacement and autoinflation; the five-year mechanical failure rate ranges from 6 to 16 percent. To reduce the risk of infection, one available inflatable device has an antibiotic coating, and the other has a hydrophilic coating. A lockout valve recently was added to some models to prevent autoinflation.
Magnetic resonance imaging (MRI) can be used to evaluate the status of a penile implant, but MRI is contraindicated in patients with ferromagnetic implants.
The surgery to implant the device should not be performed if the patient has a systemic, cutaneous, or urinary tract infection. Gram-negative and gram-positive antibiotics should be administered before surgery. The operative area should be shaved immediately before surgery, and a thorough skin preparation should be performed. General, spinal, or epidural anesthesia usually is performed.
The AUA panel does not recommend penile venous reconstructive surgery (surgeries performed to limit the venous outflow of the penis). Penile arterial reconstructive surgery remains controversial. The panel consensus is that a large study of penile arterial reconstructive surgery must be performed to determine its effectiveness. Arterial reconstructive surgery is an option only in healthy men with recently acquired ED secondary to a focal arterial occlusion who do not have any evidence of generalized vascular disease.