sinusitis
"Had a terrible sinus infection.  Got on a Zpack.  It takes until day 3 before your really start feeling like it's working.  The pack continues to work 10 days after you finish it.  I had no tummy problems like I have read on other postings, but I do make sure to eat yogurt everyday when I am on any type of antibiotic.  The probiotics in yogurt can keep you from getting loose stools.  The one thing that I did notice this time was some dizziness. Never before had that with taking a Zpac.  It was not severe dizziness, but enough to make me wonder."