TABLE 2.

Probability of attaining T>MIC target measures following standard dosing regimens of piperacillin-tazobactam and cefepime against E. coli and K. pneumoniae ESBL-producing phenotypes

RegimenP of achieving PK-PD target measuresa,b
30%40%50%60%70%
E. coli
    Piperacillin-tazobactam, 3.375 g every 4 h0.960.920.900.860.77
    Piperacillin-tazobactam, 3.375 g every 6 h0.910.860.730.500.28
    Cefepime, 2 g every 12 h1.01.01.01.00.99
    Cefepime, 1 g every 12 h1.00.990.990.980.96
K. pneumoniae
    Piperacillin-tazobactam, 3.375 g every 4 h0.770.720.650.570.48
    Piperacillin-tazobactam, 3.375 g every 6 h0.690.570.430.290.16
    Cefepime, 2 g every 12 h1.01.01.00.980.96
    Cefepime, 1 g every 12 h0.990.960.950.940.93
  • a Percentage of the dosing interval when drug concentration in serum remained above the MIC is given.

  • b Boldfaced values represent the PK-PD target ranges for each drug.