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.