Pathogen

Antibiotic and routine dosage

Alternative antibiotics

Staphylococcus aureus and methicillin-susceptible coagulase-negative staphylococci

Cefazolin 2 g IV every 8 h or cloxacillin 2 g IV every 4 h

Vancomycin

MRSA and methicillin-resistant coagulase-negative staphylococci

Vancomycin 15-20 mg/kg every 12 hb

Daptomycin (use for MRSA if vancomycin MIC ≥2 microg/mL)

Ampicillin-sensitive Enterococcus spp

Ampicillin 2 g IV every 6 h

Vancomycin

Ampicillin-resistant Enterococcus spp

Vancomycin (as above)

Daptomycin

VRE

Daptomycin 8-12 mg/kg IV daily

Linezolid

Pseudomonas aeruginosa

Ceftazidime 2 g IV every 8 h or piperacillin/tazobactam 4.5 g IV every 6-8 h

Aminoglycosides

Imipenem

Meropenem

Cefepime

Ciprofloxacin

ESBL-producing organisms and AmpC producing gram-negative bacteria (in particular Enterobacter cloacae complex, Klebsiella aerogenes, and Citrobacter freundii)

Ertapenem 1 g IV daily empirically, then based on susceptibilities

Meropenem

Imipenem

Other gram-negative organisms (eg, Escherichia coli, Klebsiella spp)

Based on susceptibilities

Candida spp

Caspofungin 70 mg IV on day 1, then 50 mg IV daily; or anidulafungin 200 mg IV on day 1, then 100 mg IV daily; then based on species and susceptibilitiesc

Fluconazole

Amphotericin

a Recommendations should be further guided by susceptibility testing as available. Doses indicated assume normal renal function and body mass.

b Serum trough levels suggested with first trough prethird or prefourth dose: levels should be 15-20 microg/mL for S aureus infection and 10-15 microg/mL for other pathogens.

c Fluconazole is suboptimal therapy in Candida krusei and Candida glabrata; use an echinocandin instead. For Candida parapsilosis, use fluconazole instead of an echinocandin.