Therapy for Women Hospitalized with Acute Pyelonephritis: A Randomized Trial of Ampicillin versus Trimethoprim-Sulfamethoxazole for 14 Days

The efficacy of the traditionally recommended ampicillin (Amp) plus gentamicin (GM) regimen was compared with that of a trimethoprim-sulfamethoxazole (TMP/SMZ)-plus-GM regimen and the adequacy of 14 days total therapy for acute uncomplicated pyelonephritis (AUPN). Eighty-five women hospitalized for AUPN were randomly assigned to receive either Amp, 1 g intravenously (iv) every 6 h for 3 days, then 500 mg orally four times daily, or TMP/SMZ, 160/800 mg iv every 12 h for 3 days, then 160/800 mg orally twice daily. Initially, all patients also received GM every 8 h iv (mean, 6.6 doses). Antimicrobial resistance necessitated modifying therapy of 14(32%) of the Amp recipients but of none of the TMP/SMZ recipients (P < .001). Both regimens produced a satisfactory bacteriologic and clinical response in all cases. Reinfection occurred in 11% ofAmp and in 8% ofTMP/SMZ recipients. Nopatient experienced relapsing infection. The TMP/SMZ regimen was less costly and less likely to require modification due to antimicrobial resistance.