It's expensive as hell, and I'd also be worried about what the long-term effects are of taking this pill for 50 years. Still, it's an interesting notion. From the NY Daily News:
Gay men who have five or more sex partners per year are part of a high-risk group that could benefit from a daily pill to ward off HIV, said a cost-benefit analysis by researchers on Monday.
The study by experts at Stanford University, published in the Annals of Internal Medicine, looked at the costs involved with prescribing a $26 a day pill to men who have sex with men.
The pill, Truvada (tenofovir-emtricitabine), was shown in a landmark 2010 trial published in the New England Journal of Medicine to prevent HIV infections in as many as 73 percent of gay men who took it regularly.