Hi Dr. Grief, I have had a sinus infection since Jan 3, 2013. I ve been to several doctors including an infectious disease doctor and an ENT. This is my first problem like this with my sinuses. I ve now been on 7 weeks worth of antibiotics (including biaxin , doxycycline , zithromax and avelox ), 14 days of prednisone, a week of flonase and lots of OTC meds. At my recent visit to my ENT, he suggested I take mucinex D and biaxin (when I m finished the course of biaxin, it will be 8 weeks worth of antibiotics). I have been running a low grade fever for the duration of the infection. A CT scan at the beginning of February showed pansinisitus and that the osteomeatal complexes were occluded by fluid. My question is about mucinex and / or mucinex - d. Is it possible for that medication to make the congestion worse? I seen to have more congestion since I started with the mucinex d. I typically drink a lot of water daily and am wondering if I should double my usual 8-10 glasses a day while on mucinex-d in order for it to work? I do follow up with the ENT next week.