[JunkDNA]

You're right about incentives being wrong, but I disagree with the preference for chronic drugs being a primary factor. In my opinion, the primary incentive killer is that agencies like the FDA will not approve a truly new antibiotic for general use. It gets approved as an antibiotic of last resort. So for the time that a new antibiotic is under patent protection, the company can't recoup their R&D because they can only address a tiny part of the market. When the day finally comes when the wonder drug can be standard of care, it's well off patent and generic competition torpedoes any real profit. Why develop a great new antibiotic if the FDA forces you to keep it locked away? From the company perspective it makes no sense.

[pak]

Hmm, well as a counterpoint to your point about the FDA, fidaxomicin was approved in 2011 for general use against C. difficile colitis, because it showed certain outcomes that compared favorably against the current standard of care (oral vancomycin) [1]. The reason it isn't used more often is probably because it is one of the most expensive antibiotics available. Antibiotics aren't typically approved only as "last resort"; it remains at the discretion of the physician to jump straight to the big guns before drug susceptibility test results are available (which is part of the problem).

[1] https://en.wikipedia.org/wiki/Fidaxomicin