bacterial infection
"Started this 4 days ago for an anaerobic infection in my jaw, that had not responded to other medication. The first I developed a severe headache at bedtime, took one of the pain pills the dentist had prescribed because of my jaw/tooth abscess. Took care of it, and went about my business. So far, every NIGHT I developed a headache an hour or so after taking my last dose of the day (1 500mg tab twice a day). This is day 4. Only other side effect I've noticed is significantly darkened urine. I would have been really worried about that (as I have kidney stones) but had a routine visit with my urologist today who said it was ok and would go away. "