Effects of gentamicin monotherapy for the initial treatment of community-onset complicated non-obstructive acute pyelonephritis due to Enterobacteriaceae in elderly and non-elderly women.

Aminoglycosides may serve as fluoroquinolone-sparing or cephalosporin-sparing agents if the clinical effectiveness of aminoglycoside monotherapy is demonstrated. The purposes of this study were to investigate the clinical efficacy of gentamicin as an initial empirical antimicrobial agent and to evaluate the effects of gentamicin resistance on clinical outcomes in women with complicated non-obstructive acute pyelonephritis (APN). Medical records of 1066 women with a diagnosis of APN were reviewed retrospectively. We enrolled 275 women with community-onset complicated non-obstructive APN due to Enterobacteriaceae who received gentamicin as their initial antibiotic. Of these 275 patients, 43 had gentamicin-resistant (GM-R) Enterobacteriaceae APN, and 232 had gentamicin-susceptible (GM-S) Enterobacteriaceae APN. The early clinical success rates were 67.4% (29/43) versus 89.7% (208/232) at 72 h in the GM-R versus the GM-S groups (p 0.001). The overall clinical cure rate was 100% (43/43) and 98.7% (229/232) in the GM-R and GM-S groups, respectively. The duration of hospital stay was significantly longer in the elderly, although there were no significant differences in the rates of early clinical success, final clinical cure, mortality, and time to fever clearance between the elderly and non-elderly groups. Resistance of Enterobacteriaceae to gentamicin, haematuria and serum C-reactive protein level≥20 mg/dL were independently associated with early clinical failure. Gentamicin can be an effective initial antibiotic option for empirical therapy in women with community-onset complicated APN who do not need urological interventional procedures. The use of gentamicin may contribute to a reduction of fluoroquinolone or broad-spectrum cephalosporin use in the treatment of complicated APN.