bacterial infection
"Started taking doxycycline for sinus infections because of other drug allergies, such as penicillin, sulfa and Cipro. I take it between breakfast and lunch and then between lunch and supper. I set up after taking and have no problems with this drug. Thank God I have something to take and my head feels better after the first dose. Hopefully, I will not develop any allergies to this. I have taken this for three times, 10 days at a time, now over the last three years with no problems."