Azithromycin
"I was prescribed azrithromycin by my Dr for sinusitis. I have suffered from year-long allergies since I was a kid & this year has definitely been a bad one for me. I was a little worried about taking this medication because I read that some people got bad stomach upset with it. Luckily enough, the worst thing that happened to me was minor lower abdominal cramps, no worse than menstrual cramps. By the time I woke up the next day I was able to breathe clear for the first time literally in months. I did not feel congested, although I did have a very minor sore throat that I believe was caused by my sinuses finally draining. 

I definitely recommend taking this drug with food --it helps avoid stomach upset or cramps. Otherwise this helped me"