Levofloxacin is an advanced generation fluoroquinolone antibiotic, marketed by Ortho-McNeil under the trade name Levaquin in the United States. In Europe, it is marketed by Sanofi-Aventis under the trade name Tavanic, in Chile as Gatigol by Alpes Selection, and in Asia it is marketed by Daiichi under the trade name Cravit. Levofloxacin was launched in the Japanese market in 1993, and thus has had more than 13 years of testing in efficiency and safety globally. Chemically, levofloxacin is the S-enantiomer (L-isomer) of ofloxacin, and has approximately twice the potency of ofloxacin. It works by inhibiting DNA gyrase, an enzyme that negatively supercoils DNA.

Levofloxacin is effective against a number of gram-positive and gram-negative bacteria. Because of its broad spectrum of action, levofloxacin is frequently prescribed.