I was on levaquin (levofloxacin) 500 mg for my sinuses but it didn't work. Now I am taking leavaquin 750 mg and 40 mg of prednisone. How long will it take to work?

Not for sinuses. Prednisone does not help with sinus problems. Levaquin (levofloxacin) 500 was too small a dose to begin with unless you have kidney problems. Antibiotics have a marginal benefit in chronic sinusitis.
Ask your physician. Prednisone will help decrease the inflammation in your sinuses, but Levaquin (levofloxacin) might not the the best drug for your situation.
It depends. There is no magic amswer tohow long medications take towork, as everyone is unique and people mteabolize medications differently. Your sinus condition could be "chronic" in nature and that would require a longer course opf antibiotics. Generally speaking though, Levaquin (levofloxacin) and steroids are 2 good medications for treating sinus infections. If you do not imporve within 1 week, see your dr.