A 64-year-old man seeks treatment for erectile dysfunction. He has been in a stable, monogamous relationship for many years. Over the last 3 years, he has had progressive difficulty attaining and maintaining an erection sufficient for successful intercourse. He relates that his sexual desire is unchanged, but he no longer has spontaneous morning erections. His medical problems include type 2 diabetes mellitus, hypertension, hyperlipidemia, and coronary artery disease.
He underwent successful angioplasty of the proximal left anterior descending artery for non-ST elevation myocardial infarction 2 years ago with a drug-eluting stent. He can walk up 4 flights of stairs and about 6 blocks at a modest pace before he has to stop due to fatigue. He has occasional episodes of angina while walking at a fast pace or in cold weather. His current medications include metformin, rosuvastatin, losartan, metoprolol succinate, clopidogrel, low-dose aspirin, and isosorbide mononitrate.
His blood pressure is 124/74 mm Hg, pulse is 64/min, and respirations are 14/min. His BMI is 31 kg/m². Cardiopulmonary and abdominal examinations are within normal limits. Femoral and peripheral pulses are 2+ and symmetric. Testes are normal size. Both feet have decreased sensation to pinprick.
Echocardiogram shows ejection fraction of 42%. He is able to walk on a treadmill to 84% of predicted maximum without chest pain or ECG changes. His systolic blood pressure does not decrease with treadmill exercise.
Laboratory testing shows normal complete blood count and a morning total serum testosterone of 340 ng/dL.
Which of the following is the best next step in management of this patient?

Question

Quizplus · Accepted Answer

11ec193a_9870_5a07_853d_0dde3fc16f27_MD0002_00 This patient presents with erectile dysfunction (ED) with intact libido and normal testosterone levels. Patients unable to have spontaneous morning erections most likely have vascular or neurogenic causes of ED. This patient exercises moderately without angina and would likely tolerate sexual activity without safety concerns. Current guidelines recommend phosphodiesterase inhibitors (PDE) as first-line therapy for ED. PDE inhibitors (eg, sildenafil, vardenafil, and tadalafil) increase cyclic guanosine monophosphate (cGMP), leading to increased nitric oxide-mediated vasodilation and erection. Nitrates stimulate guanylate cyclase, increase cGMP, and cause systemic vasodilation. Patients taking both nitrates and PDE inhibitors have increased risk for hypotension and syncope. This patient has occasional angina with excessive activity; he therefore needs to continue isosorbide mononitrate and cannot take PDE inhibitors (Choice B). Second-line therapy includes penile self-injectable drugs, intraurethral alprostadil, and vacuum devices. Most patients prefer intraurethral alprostadil, a vasodilator that increases penile blood flow to cause an erection. It is generally well tolerated with few side effects, is more convenient, has no drug interactions with nitrates, and would be the best treatment option for this patient. (Choice C) Penile prosthesis is generally reserved for patients failing or refusing other therapies (eg, intraurethral therapy, vacuum erection therapy). Prostheses are invasive with risks of infection, anesthesia, and device failure. (Choice D) This patient does not have signs and symptoms of testosterone deficiency (eg, decreased libido, depression, anemia) and has a normal testosterone level. Testosterone replacement would be harmful. (Choice E) Yohimbine is a selective alpha-2-adrenergic receptor blocker that may increase parasympathetic tone, reduce sympathetic tone, and result in an erection. However, it has limited efficacy in studies and is not recommended in patients with cardiovascular disease due to side effects such as tachycardia and hypertension. Educational objective: Phosphodiesterase inhibitors (eg, sildenafil) are contraindicated for treating erectile dysfunction in patients taking nitrates for angina due to the risks of hypotension and syncope. Treatment options for these patients include intraurethral alprostadil and vacuum assist devices. __________ References: Sildenafil citrate potentiates the hypotensive effects of nitric oxide donor drugs in male patients with stable angina. (http://www.ncbi.nlm.nih.gov/pubmed/10898408) Treatment of men with erectile dysfunction with transurethral alprostadil. Medicated Urethral System for Erection (MUSE) Study Group. (http://www.ncbi.nlm.nih.gov/pubmed/8970933)

A 64-Year-Old Man Seeks Treatment for Erectile Dysfunction