Use of Gentamicin for Women with Community-Acquired Uncomplicated Acute Pyelonephritis Caused by Gentamicin-Susceptible or -Resistant Escherichia coli: 10-Year Experience

The objectives of this study were to evaluate the clinical effectiveness of gentamicin as an initial empirical antimicrobial agent and to determine the effects of gentamicin resistance on clinical outcomes in women with uncomplicated acute pyelonephritis (APN). We analyzed data of 2,033 women with a diagnosis of APN admitted to Catholic University St. Vincent's Hospital. Of those, we enrolled 274 cases of community-acquired uncomplicated APN due to Escherichia coli who received gentamicin as initial antibiotics. Of these 274 patients, 47 patients had gentamicin-resistant (GM-R) E. coli APN, and 227 patients had gentamicin-susceptible (GM-S) E. coli APN. The early clinical response rates were 55.3% (26/47) versus 81.5% (185/227) at 72 hours; 61.7% (29/47) versus 96.9% (220/227) at 96 hours in the GM-R and GM-S groups, which was significantly higher in the GM-S group (p < 0.001). Overall clinical cure rates were 100% (47/47) and 99.6% (226/227) in the GM-R and GM-S groups, respectively. APN patients in the GM-R group had longer hospitalization (9.72 +/- 3.46 and 7.89 +/- 2.27 days; p < 0.001) than those in the GM-S group. Resistance of E. coli to gentamicin, bacteremia, and C-reactive protein level showed independent effects on early clinical failure. Aminoglycoside such as gentamicin can be an alternative antibiotic option for initial empirical therapy of community-acquired uncomplicated APN as the fluoroquinolone-sparing or broad-spectrum cephalosporin-sparing agents in an era of increasing antimicrobial resistance, especially in areas where medical resources are limited or antibiotic resistance rate of the uropathogens is high.