Table 2

Drug regimen (all 30 minute infusions)	Susceptibility breakpoint MIC (mcg/ml)
Drug regimen (all 30 minute infusions)	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	4^a	2
Meropenem 1 g q8 h	4^a	2
Piperacillin/tazobactam 3.375 g q6 h	64^b	8
Piperacillin/tazobactam 4.5 g q6 h	64^b	8

^aCLSI susceptibility breakpoints for imipenem and meropenem against P. aeruginosa were reduced to 2 mcg/ml in 2012 ^bCLSI 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].