it shouldnt do any harm but i would recommend that you take something to boost yourself while taken so many antibiotics as i suffer with kidney diseaes and i myself take an awful lot of antibiotics and they can make you ran down so try a supplement that will boost you up while your taken the course of treatment hope this helps gud luck !!
I agree, stick with the doctor's opinion. The mouth infection may be fungal (look up 'thrush',pretty common on TX) and the antibiotics won't work on a fungal infection, only bacterial infections. You could call and describe it and he may call in an anti-fungal mouth rinse for you.
I think that sounds something more like your doctor should answer than any of us. We're just patients and loved ones of hep and really aren't qualified to give medical advice. We can really only give our experiences and opinions in here - otherwise we aren't getting paid enough ;)