Traditional antibiotic therapy is not effective against chronic sinus infections. There is no blood flow in the sinuses -they are hollow caves in the face. Antibiotics can sometimes be effective against acute sinus infections, specifically if there is lung involvment. Antibiotics have an anti-inflammatory effect that can help the sinuses drain.

One option for you is Nebulized Antibiotics which theoretically attack the bacteria directly.

But a much better idea is sinus irrigation using a machine, 3ml of hydrogen peroxide, 5ml of Alkalol, and a tablespoon of Xyletol, 4 times a day for 3 days. Then remove the peroxide and continue doing this for 2 times a day.

Another option is IV antibiotics, but that would be a last resort.

have you had sinus surgery?

I should point out that 28 days on Levaquin in EXTREMELY dangerous. This is a medication with a lot of really bad, potentially life-threatening, side-effects. People who take it long term can end up in a wheelchair with ruptured tendons in the legs, vasculitis, peripheral neuropathy, and all sorts of serious health issues. The floroquinolones (Cipro, Avelox, and Levaquin) are propbably the most dangerous drugs on the market.

Your muscle issues may be a result of the Levaquin.

Also, these drugs should NEVER be taken with systemic steroids (Prednisone, Medrol, etc.). Bayer, et. al. are very specific about this. But I see ENTs making this mistake all the time.