USES: Gatifloxacin is used to treat a variety of bacterial infections. It works by stopping the growth of bacteria. This medication belongs to a class of drugs called quinolone antibiotics. This antibiotic only treats bacterial infections. It will not work for viral infections (e.g., common cold, flu). DRUG INTERACTIONS: This drug should not be used with the following medications because very serious interactions may occur: certain antiarrhythmics (e.g., quinidine, procainamide, amiodarone, dofetilide, sotalol). If you are currently using any of these medications, tell your doctor or pharmacist before starting gatifloxacin.