It was found that finafloxacin eradicates pathogens from patients suffering from bacterial infections like urinary tract infections and pyelonephritis more quickly than other fluoroquinolones regularly used for the treatment of these patients. Due to the efficacy of finafloxacin reduced treatment durations without increasing the daily dosage of finafloxacin and at the same time no or shorter stays in hospital are realizable, thus improving patient convenience and significantly lowering the costs of hospitalization and treatment. Reduced hospitalization periods do also clearly reduce the risk of nosocomial infections and of generating drug-resistant strains through extended therapy. The inventive treatment regimens comprise an oral finafloxacin administration for 1-5 days or a parenteral finafloxacin administration for 1-5 days for use in the treatment of a complicated urinary tract infection or pyelonephritis. However, a prior short parenteral administration of finafloxacin (e.g. 3 days) in combination with an oral administration (e.g. 2 days) may be applied, if necessary in case of really severe infections. The present invention further relates to a novel treatment regime for the treatment of uncomplicated UTI whereby a single oral finafloxacin dose is considered to be sufficient to effectively treat patients with uncomplicated UTI.
