Chapter 049. Sexual Dysfunction (Part 5) Male Sexual Dysfunction: Treatment Patient Education Patient and partner education is essential in the treatment of ED. In goal- directed therapy, education facilitates understanding of the disease, results of the tests, and selection of treatment. Discussion of treatment options helps to clarify how treatment is best offered and stratify first- and second-line therapies. Patients with high-risk lifestyle issues, such as smoking, alcohol abuse, or recreational drug use, should be counseled on the role these factors play in the development of ED. Oral Agents Sildenafil, tadalafil, and vardenifil are the only approved and effective oral agents for the treatment of ED. These three medications have markedly improved the management of ED because they are effective for the treatment of a broad range of causes, including psychogenic, diabetic, vasculogenic, postradical prostatectomy (nerve-sparing procedures), and spinal cord injury. They belong to a class of medications that are selective and potent inhibitors of PDE-5, the predominant phosphodiesterase isoform found in the penis. They are administered in graduated doses and enhance erections after sexual stimulation. The onset of action is approximately 60–120 min, depending on the medication used and other factors such as recent food intake. Reduced initial doses should be considered for patients who are elderly, taking concomitant alpha blockers, have renal insufficiency, or are taking medications that inhibit the CYP3A4 metabolic pathway in the liver (e.g., erythromycin, cimetidine, ketoconazole, and, possibly, itraconazole and mibefradil), as they may increase the serum concentration of the PDE-5 inhibitors or promote hypotension. Testosterone supplementation combined with a PDE-5 inhibitor may be beneficial in improving erectile function in hypogonadal men with erectile dysfunction who are unresponsive to PDE-5 inhibitors alone. These drugs do not affect ejaculation, orgasm, or sexual drive. Side effects associated with PDE-5 inhibitors include headaches (19%), facial flushing (9%), dyspepsia (6%), and nasal congestion (4%). Approximately 7% of men using sildenafil may experience transient altered color vision (blue halo effect), while 6% of men taking tadalafil may experience loin pain. PDE-5 inhibitors are contraindicated in men receiving nitrate therapy for cardiovascular disease, including agents delivered by oral, sublingual, transnasal, or topical routes. These agents can potentiate its hypotensive effect and may result in profound shock. Likewise, amyl/butyl nitrate "poppers" may have a fatal synergistic effect on blood pressure. PDE-5 inhibitors should also be avoided in patients with congestive heart failure and cardiomyopathy because of the risk of vascular collapse. Because sexual activity leads to an increase in physiologic expenditure [5–6 metabolic equivalents (METS)], physicians have been advised to exercise caution in prescribing any drug for sexual activity to those with active coronary disease, heart failure, borderline hypotension, or hypovolemia, and to those on complex antihypertensive regimens. Although the PDE-5 inhibitors share a common mechanism of action, there are a few differences among the three agents. Having been on the market the longest, sildenafil has the most robust data confirming its activity, safety, and tolerability. It has recently been released for use in pulmonary hypertension as well as ED. Tadalafil is unique in its longer half-life. All three drugs are effective for patients with ED of all ages, severities, and etiologies. While there are pharmacokinetic and pharmacodynamic differences among these agents, clinically relevant differences are not clear. Androgen Therapy Testosterone replacement is used to treat both primary and secondary causes of hypogonadism (Chap. 340). Androgen supplementation in the setting of normal testosterone is rarely efficacious and is discouraged. Methods of androgen replacement include transdermal patches and gels, parenteral administration of long-acting testosterone esters (enanthate and cypionate), and oral preparations (17 α-alkylated derivatives) (Chap. 340). Transdermal delivery of testosterone using patches or gels (50–100 mg/d) more closely mimics physiologic testosterone levels, but it is unclear whether this translates into improved sexual function. The administration of 200–300 mg intramuscularly every 2–3 weeks provides another option but is far from an ideal physiologic replacement. Oral androgen preparations have the potential for hepatotoxicity and should be avoided. Testosterone therapy is contraindicated in men with androgen-sensitive cancers (e.g., prostate) and may be inappropriate for men with bladder neck obstruction. It is generally advisable to measure PSA before giving androgen. Hepatic function should be tested before and during testosterone therapy. Vacuum Constriction Devices Vacuum constriction devices (VCD) are a well-established, noninvasive therapy. They are a reasonable treatment alternative for select patients who cannot take sildenafil or do not desire other interventions. VCD draw venous blood into the penis and use a constriction ring to restrict venous return and maintain tumescence. Adverse events with VCD include pain, numbness, bruising, and altered ejaculation. Additionally, many patients complain that the devices are cumbersome and that the induced erections have a nonphysiologic appearance and feel. . Chapter 049. Sexual Dysfunction (Part 5) Male Sexual Dysfunction: Treatment Patient Education Patient and partner education. function in hypogonadal men with erectile dysfunction who are unresponsive to PDE-5 inhibitors alone. These drugs do not affect ejaculation, orgasm, or sexual drive. Side effects associated with. Because sexual activity leads to an increase in physiologic expenditure [5–6 metabolic equivalents (METS)], physicians have been advised to exercise caution in prescribing any drug for sexual