Treatment for Carbapenem-Resistant Organism (CRO) Pseudomonas Bacteremia

General Management Principles

The Infectious Diseases Society of America recommends infectious disease consultation for management of infections caused by multidrug-resistant organisms (MDRO) 3, 4
Antimicrobial susceptibility testing is essential to guide appropriate antibiotic selection for CRPA infections, as recommended by the European Society of Clinical Microbiology and Infectious Diseases 3, 5
Prolonged infusion of β-lactams is recommended for pathogens with high minimum inhibitory concentrations (MICs) by the International Society for Antimicrobial Chemotherapy 3, 4

The American Society for Microbiology suggests ceftolozane-tazobactam as the preferred therapy for difficult-to-treat CRPA infections if active in vitro 1, 2, 6
Newer agents such as imipenem-relebactam, cefiderocol, and ceftazidime-avibactam may be considered for CRPA bacteremia, though evidence for their use is limited, according to the Clinical Microbiology and Infection guidelines 1, 2

For severe CRPA infections treated with older agents, combination therapy with two in vitro active drugs is recommended by the European Society of Clinical Microbiology and Infectious Diseases 1, 2
No specific combination regimen has demonstrated superiority over others; selection should be based on susceptibility testing, as stated by the Infectious Diseases Society of America 1, 6

When polymyxins are used for CRPA bacteremia, combination therapy is preferred over monotherapy, according to the Journal of Microbiology, Immunology and Infection 7
Colistin dosing for patients with normal renal function typically includes a loading dose of 300 mg colistimethate sodium followed by maintenance doses of 300-360 mg divided into two daily doses, as recommended by the European Society of Clinical Microbiology and Infectious Diseases 7

Obtain appropriate cultures and antimicrobial susceptibility testing before initiating therapy, as recommended by the Infectious Diseases Society of America 3, 5
Consult infectious disease specialists early in the management, according to the European Society of Clinical Microbiology and Infectious Diseases 3, 4
For severe CRPA bacteremia, use ceftolozane-tazobactam if susceptible, as suggested by the American Society for Microbiology 1, 2
If ceftolozane-tazobactam is not available or the organism is resistant, consider other newer agents based on susceptibility, according to the Clinical Microbiology and Infection guidelines 1, 2

Tigecycline should not be used for bloodstream infections due to inadequate serum concentrations, as stated by the European Society of Clinical Microbiology and Infectious Diseases 6, 7
Monotherapy with polymyxins or aminoglycosides for severe CRPA bacteremia is associated with higher treatment failure rates, according to the Infectious Diseases Society of America 1, 7