Why does TCCC guidelines use the antibiotics it uses....
Good questions. The answer is moxifloxacin appears to be a compromise choice, not a perfect choice. I have attached the 2011 IDSA guidelines for combat wound which goes into more detail on what to use when. I think moxi is a reasonable choice (I cant speak for the committee here but...)
1) moxi will cover for staph (MSSA) and coag neg staph, strep, Aeromonas spp (water contaminate), Acinetobacter and coliforms. Clinda does offer better MRSA (Moxi and cefixime do not), but neither clinda nor cefixime will cover Aeromonas or Acinetobacter. Clinda does not cover coliforms.
2) IDSA recommends narrow spectrum (gen 1 ceph) as base for combat injuries with exception of occular injury. (they do recommend addition of flagyl in some circumstances such as abd wounds). By using moxi you are meeting the abx within 3 hours guideline and you cover injury to almost all body areas with 1 pill.
3) Overall risk of tendonopathy with a single dose in an otherwise healthy young pt is actually pretty low. Check out this paper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2921747 which sites risk of tendonopathy at 3.8 fold increase compared to other abx with avg age of incidence at 64 y/o.
4) Finally, you are correct. Meloxicam has a comparatively lower antiplatelet effect compared to other NSAIDs, not a zero effect. It is a choice of lesser evils. You get an additiive effect with the tylenol and meloxicam, might be able to avoid narcs or ketamine and so the payoff may be worth it.
This is just a quick answer, but I hope it helps. If not please let me know and I'll keep looking for you!