I have pneumonia and was prescribed 750mg Levoquin. After reading the FDA warnings I got very nervous because my muscles were sore and asked to change antibiotics after taking only 1 pill. I am allergic to penicillin (anaphylaxis) so I was prescribed Doxycycline 100mg which I have been taking x2 daily for 6 or 7 days but I still have chest pain and can't imagine I will be better in 3 days. I don't have $ for doctor again so now I just want to know if I should switch back to the Levoquin for the last 3 or 4 days.