How does trimethoprim-sulfamethoxazole's efficacy against S. pyogenes influence your empirical treatment of skin infections in regions with high resistance rates?

Recommendations against using trimethoprim-sulfamethoxazole (TMP/SMX) for group A strep (GAS) skin and soft tissue infections (SSTIs) likely stemmed from a misconception that GAS is inherently resistant to the drug. Older studies reporting resistance used media containing a high thymidine concentration, which is known to inactivate TMP/SMX, or did not provide enough information about the media used for testing isolates. (McCreary et al., PMID 37310038; Bowen et al., PMID 29255730). The 2014 IDSA...

I am a little confused by the question. Why would you use TMP/SMX monotherapy for SSTI? During the emergence of CA-MRSA, cephalexin with or without TMP/SMX had the same efficacy rates (Pallin). I agree with Dr. @Dr. First Last; linezolid is a great choice if MRSA is a concern. Cephalexin or cefadroxil are fine if MRSA isn't a concern or if the patient can be followed closely. Second- and third-generation FQs have good activity against strep and staph. Omadacycline effectively treats cellulitis, ...

Why I Still Don’t Understand Using TMP/SMX for SSTIs.

TMP/SMX has poor clinical activity against Gram-positive cocci to begin with. But the bigger issue is how it’s almost always dosed in practice. For SSTIs, Doctors prescribe Bactrim DS, 1 PO BID— the appropriate dose for cystitis, but nowhere near adequate for Group A Strep or S. aureus skin and soft-tissue infections. Remember, SSTI efficacy trials are difficult, since people often recover without antibiotic therapy.

We have so many better o...