It seemed to begin with a 2 day headache. As I had a severe UTI, I was not sure if the symptoms I was having were because of the Levaquin or the infection. The headache was the first "unusual" symptom I had within 1 hour of taking the Levaquin. Then the muscle aches, tendon pain, arches of feet hurt, arthritis in hands became more painful than I had ever experienced, very fatiqued, skin sensitive to touch, tingling sensation on arms, racing heartbeat (may have been due to anxiety of other symptoms). These symptoms continued for 6 days until 24 hours after stopping medication. I discontinued it after researching side effects on internet as Patient Information sheet that came with medication was vague. I still have tendon pain in left elbow, and arches of feet. Amazingly, I have had knee surgery and back surgery, but neither of these areas seemed to have been affected. Still don't feel "right", but hopeful will continue to improve.