This study was one of the first to examine the in vivo levofloxacin adsorption to stent surfaces. The results demonstrated the ability of this antibiotic to adsorb to the conditioning film and to the surface of the inserted device, and showed that 1-2 weeks after the discontinuation of antibiotic administration some amount of the antibiotic still could be detected on them. The second aim of the investigation was to determine whether continuous or intermittent levofloxacin treatment is advantageous for the patients who have acute complicated urinary tract infection (UTI) caused by urinary obstruction. The results did not show any clinical or microbiological advantages of the continuous therapy.