A clinical study on combination therapy of antimicrobial agents for complicated urinary tract infection--with special reference to combination with clarithromycin

Abstract

To confirm the clinical efficacy of the combined therapy to complicated urinary tract infection (UTI), we conducted a comparative clinical study of the combined therapy with ciprofloxacin (CPFX) and clarithromycin (CAM) acting an biofilm elimination or CPFX alone in patients with complicated UTI. The study was carried out in patients with complicated UTI having WBCs with 5/hpf or more in urinary sediment and bacteriuria at least 10(4) CFU/ml. The combined therapy was CPFX and CAM, each 600 mg/day, for 14 days, and the single therapy group CPFX, 600 mg/day, for 14 days. On Day 7 and 14, the eradication rate and efficacy rate (according to the criteria of the Japanese UTI committee) were determined. In the patients with indwelling catheter, the surface of the catheter tip was observed under a scanning electron microscope (SEM) on Day 14. In both cases with and without catheters, clinical efficacy was higher in the combined therapy group than in the single therapy group. In particular, the efficacy rates at 14 Day were significantly higher in the former group. Furthermore, we investigated the therapeutic effect in the below MIC breakpoint of CPFX in complicated UTI. The combined therapy group showed a higher clinical efficacy in both cases with and without indwelling catheter than the single therapy group, although there was not statistically significant. Biofilm on the surface of the catheter tip was eliminated in 75% of the combined therapy group. However, none of the biofilm was eliminated in the single therapy group. From the above results, we surmise that the combined use of CPFX and CAM will show some degree of efficacy in eliminating both the causative organism and its biofilm in the complicated UTI.