ED drugs have won over the American College of Physicians. The primary care doctors' group reviewed evidence from 130 controlled trials to decide that the meds are quite effective and very safe, causing only mild side effects--provided patients don't have any of the risk factors that prohibit their use, such as unstable heart disease.
But as the Wall Street Journal Health Blog notes, there's not much in the way of comparative data. So there's not much evidence to help docs determine which of the three ED meds--Pfizer's Viagra, Bayer's Levitra, and Eli Lilly's Cialis--work best in which patients. "The evidence is insufficient to compare the efficacy and adverse effects" because "few head-to-head trials are available," the college's new guidelines say.
No surprise there. Few drugmakers undertake head-to-head studies because there's too much to lose. And the FDA requires that new drugs prove better than placebo, not better than other medications already on the market. As you know, there's some federally funded comparative-effectiveness research in the works. But to our knowledge, ED meds aren't among the U.S. government's top priorities.