sinusitis
"Had been sick for going on a month now, First round of antibiotics was Amoxicillin 875 for 5 days. It worked up until day 5 and then had one of the worst rebounds I have experienced in a while. I am only on day 2 and I haven't felt this clear in months. I am a bit paranoid about the tendon and muscle warnings since I play soccer so I simply won't be doing any strenuous activities for a while. Then again, I tend to freak out when the slightest thing happens to me so we'll just see. 
You MUST drink lots of water with this Medicine.. it will surely dry you out. I was taking this with Allegra D 24 hour... and so far so good. Hopefully side effects won't be too bad if any at all. It does make you really tired though."