bacterial infection
"Omg.  I wish I would have read this two days ago!  I was prescribed this at 300 mg every 8 hours for an abscessed tooth.  Two days ago.
I literally feel like I have the flu!   Absolutely no pain relief and the swelling  in my jaw is exactly the same.   On top of that my dentist is closed till Monday (today is Wednesday).
I've been drinking water and taking it with food.   NEVER AGAIN."