As stated before, while in hospital I was on IV Zosyn for 5 days every 8 hours and vancomycin 2 x daily, then after discharge, for 16 days to prevent cdiff from the antibiotics. I had no side effects from it. I don't know which of those antibiotics removed the phlegm. Maybe it was the Vanco if the Zosyn is not doing anything for you. Hard to tell. But also, everybody is different.
I was not put on Ertapenem until after I was discharged, the phlegm had already gone away.