bacterial infection
"I had a sinus/ear issue for some time now, worse at times. This last time the Z pack did not help, along with amoxicillin. Sinus always returned until doctor prescribed doxycycline which took about 5 days to get going - prescription for 10 days. The side effect for me was some chest pain and some anxiety taking into account I developed ulcer pain/problems. The chest pain decreased after a week or so. Will stick it out 10 days hope the sinus/ear infections don't come back."