Agreed IV Vancomycin is the drug of choice against MRSA infections. Staph Aureus colonizes on the nasopharynx and is often either a respiratory tract or skin pathogen. PO Vancomycin has no effect on the respiratory tract or skin, only superficial layers of the GI system as it is non-absorbable.
If you misunderstand this, you're missing the main reason why both Vancocin (PO Vancomycin - NOT IV) and Fidaxomicin are supposed to have very low #s of systemic adverse reactions, because they are not absorbed systemically.
This is also the crux of the liver enzyme/hyperuricemia controversy. If these drugs are not absorbed systemically, then how did they elevate liver enzymes or cause high urate levels in the blood stream? I'm not sure what the details were - I have not been able to find them, simply read the results and not which patients and which number had what.