Erectile dysfunction (ED) is a common disorder of male sexual function that affects all age groups, especially older people and those with diabetes, vascular diseases, psychiatric disorders, and possibly hypogonadism. The general population continues to age and life expectancy is expected to increase. When combined with the high prevalence of diabetes and cardiovascular disease, the healthcare burden and quality-of-life issues associated with ED may be substantial. In 1995, more than 152 million men throughout the world had experienced ED, and its prevalence is predicted to reach 322 million worldwide by 2025. Furthermore, recent estimates suggest that the cost of treating ED in the United States could reach $15 billion if all affected men sought care.
Current pharmacologic therapies for ED include phosphodiesterase-5 (PDE-5) inhibitors and hormonal treatment. On November 3, 2009, the American College of Physicians (ACP) published a guideline in the Annals of Internal Medicinebased on systematic reviews and current evidence, which presents recommendations on hormonal testing and pharmacologic management for ED.
Initiating & Selecting Therapy
The ACP strongly recommends that therapy with a PDE-5 inhibitor be initiated in men who seek treatment for ED and who do not have a contraindication for using these drugs (Figure). Oral PDE-5 inhibitors have demonstrated statistically significant and clinically relevant improvements in sexual intercourse and erectile function. Overall, PDE-5 inhibitors were well tolerated and were associated with mild or moderate adverse events. The incidence of adverse events did not significantly differ among the available PDE-5 inhibitors. Nitrate therapy, however, is a contraindication for therapy with oral PDE-5 inhibitors. The ACP also recommends that clinicians base their choices of a specific PDE-5 inhibitor on the individual preferences of men with ED. Evidence is insufficient to compare efficacy and adverse effects of different PDE-5 inhibitors, so clinicians should consider individual preferences such as ease of use, cost of medication, and adverse effects profiles.
Some Questions Remain
The ACP does not recommend for or against the routine use of hormonal blood tests or hormonal treatment when managing ED because there is inconclusive evidence to determine the net benefits and harms. In studies of men with ED, the prevalence of low testosterone varies widely, ranging from 12.5% to 36.0%. The evidence is inconclusive about the effectiveness of hormonal treatment, even in patients with low testosterone. Trials comparing testosterone (delivered in various forms) with placebo in hypogonadal men with ED were small, had low quality, or reported inconsistent effects on erectile function. Considering these lingering questions, clinicians should individualize decisions to measure hormone levels. When deciding whether or not to measure hormone levels, consider the presence or absence of clinical symptoms of hormonal dysfunction (eg, decreased libido, premature ejaculation, or fatigue) and of physical findings (eg, testicular or muscle atrophy).
In addition to researching more deeply into hormonal tests and treatments, it’s also paramount that future research endeavors improve upon the quality of reporting. Some studies have evaluated the dose-response effect of PDE-5 inhibitors with respect to efficacy and harms, but more high-quality studies would be beneficial. Also, evidence regarding the incidence of adverse events appears to be limited and inconclusive. More head-to-head trials are needed to explore differences in adverse events, especially those that are more severe. As more data emerges in this field, the hope is that the burden of managing ED will improve in the years to come.