yeah, those resisistent sinus infections can be frustrating. I have had a sinus infection for a couple of months now. Was on biaxin which helped with most of it, but not all. Then doc put me on levaquin which started working but I developed an allergic reaction to it and I can't take it. I also can't take penecilin or amoxycilin or doxycyclin or tetracyclin or c chlor or tetracyclin. I'm not allergic to erthymiacin meaning that it lets me breath, but it does make me projectile vomit so I like to avoid it. Bactrim never works on sinus infections for me. I took zithromax once and it worked well. I think I am supposed to avoid things like cephalosporin too. I don't remember if I am allergic to those or not. Doctor didn't want to put me on anything else right now because it is a mild sinus infection but now that allergy season is here I miss breathing properly. I'll probably either need a CT scan or go see my old allergist. Aren't there any natural ways to kill these things? I'm already doing saline rinses too which sometimes help.