Diagnosis

Common

Pathogens

Drug(s) of

First Choice1

Alternative

Drug(s)1

Comments

INTRA-ABDOMINAL INFECTIONS

SBP (Spontaneous Bacterial Peritonitis)

E. coli

Klebsiella

Strep. spp.

Ceftriaxone5 1g IV daily

 

 

For severe PCN allergy3:

Vancomycin2

+

Aztreonam5 2g IV q8h

Gram stain recommended

 

In patients who have received previous courses of antibiotics consider expanding coverage.

Secondary Peritonitis

Mild-Moderate intra-abdominal abscess

 

 

E. coli

Klebsiella

B. fragilis

Strep spp

Staph aureus

Ertapenem 1gm IV daily

OR

Piperacillin/

Tazobactam6 (Zosyn®) 4.5g q8h

For severe PCN allergy3:

Metronidazole 500 mg IV/PO q8h

Plus one of:

Aztreonam6 2g IV q8h

OR

Gentamicin2

All with:

Vancomycin

 

Severe (major peritoneal soilage, large or multiple abscesses, patient hemodynamically unstable) or healthcare-associated

E. coli

Klebsiella

B. fragilis

P. aeruginosa

Enterococcus

Strep spp

Staph aurues

Vancomycin

Plus

Piperacillin/

tazobactam6 (Zosyn)

4.5 g IV q6-8h

WITH OR WITHOUT*

Gentamicin2

 

For severe PCN allergy3:

Vancomycin2

Plus one of:

Aztreonam6 2g IV q8h

OR

Gentamicin2

All with:

Metronidazole 500 mg IV q8h

ID consultation is recommended

 

*Consider adding gentamicin for patients with hemodynamic instability or risk of drug-resistant pathogens