Levofloxacin is used to treat certain infections such as pneumonia, and kidney, prostate (a male reproductive gland), and skin infections. Levofloxacin is also used to prevent anthrax (a serious infection that may be spread on purpose as part of a bioterror attack) in people who may have been exposed to anthrax germs in the air, and treat and prevent plague (a serious infection that may be spread on purpose as part of a bioterror attack. Levofloxacin may also be used to treat bronchitis, sinus infections, or urinary tract infections but should not be used for bronchitis and certain types of urinary tract infections if there are other treatment options available. Levofloxacin is in a class of antibiotics called fluoroquinolones. It works by killing bacteria that cause infections. Antibiotics such as levofloxacin will not work for colds, flu, or other viral infections. Using antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.