Drug regimen (all 30 minute infusions)

Susceptibility breakpoint MIC (mcg/ml)

CLSI

Pharmacodynamic

Cefepime 1 g q12 h

8

2

Cefepime 2 g q12 h

8

4

Cefepime 2 g q8 h

8

16

Ceftazidime 1 g q8 h

8

8

Ceftazidime 2 g q8 h

8

16

Imipenem 1 g q8 h

4a

2

Meropenem 1 g q8 h

4a

2

Piperacillin/tazobactam 3.375 g q6 h

64b

8

Piperacillin/tazobactam 4.5 g q6 h

64b

8

aCLSI susceptibility breakpoints for imipenem and meropenem against P. aeruginosa were reduced to 2 mcg/ml in 2012
b
CLSI susceptibility breakpoints for piperacillin/tazobactam against P. aeruginosa were reduced to 16 mcg/ml in 2012
Table 2: Clinical Laboratory Standards Institute (CLSI) susceptibility breakpoints for several β lactam antibiotics against Pseudomonas aeruginosa versus pharmacodynamics derived breakpoints, which are based on the ability for a dosing regimen to attain the fT>MIC exposure threshold for all bacteria defined as susceptible. Derived from DeRyke and colleagues [51].