In this controlled, randomized clinical trial we compared
piperacillin and
carbenicillin in the treatment of complicated
urinary tract infections. 24 patients received
piperacillin 150 mg/kg/day for 7.2 +/- 2.75 days and 17 patients received
carbenicillin 200 mg/kg/day for 7.5 +/- 2.90 days. Patients were evaluated for clinical and bacteriologic responses and tolerance to
therapy. Although the clinical cure rate significantly favored
carbenicillin treatment (p less than 0.01), the sum of the percentages of cases with clinical cure and clinical improvement were similar between groups: 91.6% for
piperacillin and 88.2% for
carbenicillin. The bacteriologic cure rates for
piperacillin and
carbenicillin patients (54.1 and 47.0%, respectively) were not significantly different (p greater than 0.05). The low cure rates in our study were probably the result of uncorrected/uncorrectable genitourinary tract abnormalities.
Superinfections developed in 12.5 and 17.6% of
piperacillin and
carbenicillin patients, respectively, and were due to Klebsiella
pneumonia, Proteus mirabilis, Citrobacter diversus, and Pseudomonas aeruginosa. Overall, side effects were mild, reversible, and did not require discontinuation of treatment. However,
carbenicillin caused elevations in liver
enzymes more frequently than
piperacillin (p less than 0.05). Based on our data, we recommend reserving
piperacillin monotherapy for patients who are poor candidates for
aminoglycosides, or are on severe
sodium restriction, and have serious complicated
urinary tract infections due to susceptible organisms. We do not recommend
piperacillin alone for empiric treatment of complicated
urinary tract infections.