Impact of discordant empirical therapy on outcome of community-acquired bacteremic acute pyelonephritis

Objectives: As ciprofloxacin resistance rate of Escherichia coli causing urinary tract infections has been increasing, concern about inappropriate empirical therapy has been arisen. Methods: We performed a retrospective cohort study to determine the impact of discordant empirical antimicrobial therapy on outcome of community-acquired bacteremic acute pyelonephritis. Results: Among a total of 164 cases included, ciprofloxacin was empirically used in 80.5%. The most frequent etiologic organism was E. coli (92.1%), of which 20.5% was resistant to ciprofloxacin. Discordant empirical therapy was documented in 29 cases, which included 25 cases caused by ciprofloxacin-resistant E. coli. Discordant therapy resulted in lower early clinical response rate (34.5% vs. 82.2%; P < 0.001) and longer hospital stay (13.3 days vs. 8.7 days; P = 0.002) compared to concordant therapy. However, overall mortality and clinical cure rate did not differ between two groups. Multivariate analyses showed that worse early clinical response was associated with discordant empirical therapy (OR, 11.08; 95% CI, 4.37-28.07) and presentation with septic shock (OR, 8.52; 95% CI, 1.75-41.49). Longer hospital stay was also associated with discordant empirical therapy (OR, 2.47; 95% CI, 1.04-5.84). Conclusions: Discordant empirical therapy, mostly with ciprofloxacin, leads to worse early clinical response and longer hospital stay than concordant therapy in community-acquired bacteremic acute pyelonephritis, although it does not affect on overall mortality or clinical cure rate. (C) 2010 The British Infection Association. Published by Elsevier Ltd. All rights reserved.