It is estimated that erectile dysfunction (ED) affects approximately 30 million men in the US, with nearly 50% of men affected aged 40−70 years. Sildenafil has been shown to be a well-tolerated and efficacious oral therapy since its 1998 approval for use in men with ED of various etiologies. Consequently, sildenafil has contributed to the debate about appropriate insurance coverage of drugs within pharmacy-benefit plans. US-based investigators evaluated the economic effect of sildenafil coverage on prescription benefit plans across the US, and presented their findings at the 8th International Meeting of the International Society for Pharmacoeconomics and Outcomes Research [Arlington, Virginia, US; May 2003].