I had racing pulse, heart pain, headache and nausea the first time I was prescribed Levaquin for a UTI. I called the doc's office and was told I it had nothing to do with the med. I took it, all the while feeling miserable, for the whole prescibed dose. I was prescribed it again, and had similar reaction, called and asked about it, and was told that my culture came back negative and I should stop taking the med. I was happy to do so. Third time it was pneumonia. I got a shot first of a penicillin derivitive, then was prescribed Levaquin. Within 24 hours I had severe hives, along with feeling awful, which my have just been related to the pneumonia. Went in to the doc, and was taken off the Levaquin, and told to never take any of this class of drug again, because my doc said the next reaction could be much worse. I was switched to a penicillin derivitive and put on a prednisone pack for the hives, which took a couple of weeks to go away even after stopping the Leviquin.