from my own clinical experience i do not find zithromax strong enough for sinusitis. sinusitis can be very difficult to treat and relapses are common. i once had to remain on antibiotics for three months for my own infection. you need to call your medical provider again. i suspect you are going to need another course of a different antibiotic (even though your mucous is clear).
7 weeks ago i got a sinus infection. zithromax helped thin the mucus but the congestion has lingered. what can i do?