sinusitis
"Second antibiotic I've been on for this sinus infection (Z-pack didn't clear it up).  I am slowly getting better, but I have all the unpleasant but evidently not dangerous side effects, nausea, dizziness, dry mouth, sour taste in my mouth. I dread taking the pill, because for the next two hours I have to lay my head on my desk because of nausea and dizziness. Even at night, I go to sleep, but wake up three hours later feeling like I'm going to vomit."