Anaphylaxis due to intravenous levofloxacin with tolerance to garenoxacin.

Fluoroquinolones are widely used in the management of infectious diseases, and are generally safe and well tolerated. However, immediate hypersensitivity reactions, including anaphylactic reactions, have been reported. We present here a case of anaphylactic shock in a 26-year-old man following intravenous levofloxacin administration. Skin tests confirmed an immediate hypersensitivity reaction to levofloxacin. Subsequent oral challenge tests for garenoxacin, which showed negative skin test results, confirmed that garenoxacin was well tolerated. This is the first report of tolerance to full-dose garenoxacin in a patient who developed an immediate hypersensitivity reaction to levofloxacin.