What antibiotic is used to treat Klebsiella infections?

Antibiotic Treatment for Klebsiella Infections

For Klebsiella infections, carbapenems (meropenem, imipenem) are the first-line treatment, with newer β-lactam/β-lactamase inhibitor combinations like ceftazidime-avibactam or meropenem-vaborbactam recommended for carbapenem-resistant strains. The optimal antibiotic choice depends on the resistance pattern of the specific Klebsiella isolate, infection severity, and local epidemiology.

Treatment Algorithm Based on Resistance Pattern

1. Susceptible Klebsiella (non-ESBL, non-carbapenemase producing)

• First-line options:
  • Third-generation cephalosporins (ceftriaxone, cefotaxime)
  • Fluoroquinolones (if susceptible)
  • Piperacillin-tazobactam

2. ESBL-producing Klebsiella

• First-line options:
  • Carbapenems: meropenem 1g IV q8h, imipenem 1g IV q8h, or ertapenem 1g IV daily 1
  • For less severe infections: consider carbapenem-sparing options based on susceptibility (fosfomycin, aminoglycosides)

3. KPC-producing Carbapenem-resistant Klebsiella

• First-line options:
  • Ceftazidime-avibactam or meropenem-vaborbactam 2
  • Strong recommendation with moderate certainty of evidence 2

4. Metallo-β-lactamase (MBL) producing Klebsiella

• First-line options:
  • Cefiderocol 2
  • Ceftazidime-avibactam plus aztreonam combination 1
  • Conditional recommendation with low certainty of evidence 2

Treatment Based on Infection Severity

Critically Ill Patients (Septic Shock)

• For suspected ESBL or carbapenem-resistant Klebsiella:
  • Meropenem 1g IV q8h or imipenem 1g IV q8h 2
  • Consider adding an aminoglycoside for synergistic effect 1, 3
  • For KPC-producers: ceftazidime-avibactam 2.5g IV q8h or meropenem-vaborbactam 2, 4

Non-severe Infections

• For susceptible isolates: Consider carbapenem-sparing regimens based on susceptibility
• For carbapenem-resistant strains: Use an active old antibiotic chosen based on susceptibility and infection site 2
• For UTIs: aminoglycosides (including plazomicin) may be effective 2, 1

Important Clinical Considerations

Resistance Mechanisms

• Knowledge of the specific carbapenemase is crucial for treatment selection 2:
  • KPC-type: Use ceftazidime-avibactam or meropenem-vaborbactam
  • MBL-type: Use cefiderocol or ceftazidime-avibactam plus aztreonam
  • OXA-48-like: Use ceftazidime-avibactam

Combination Therapy

• For severe infections with highly resistant strains (susceptible only to polymyxins, aminoglycosides, tigecycline, or fosfomycin), combination therapy is suggested 2
• Monotherapy is sufficient for infections treated with newer agents like ceftazidime-avibactam, meropenem-vaborbactam, or cefiderocol 2

Pitfalls to Avoid

1. Delayed appropriate therapy: Rapid testing for specific carbapenemases is strongly recommended to guide early appropriate therapy 2
2. Inappropriate use of tigecycline: Not recommended for bloodstream infections or pneumonia due to poor outcomes 2
3. Overreliance on carbapenems: Can promote further resistance; use carbapenem-sparing options when appropriate 1
4. Failure to adjust for renal function: Particularly important with aminoglycosides and newer agents 1

Monitoring and Duration

• For documented infections, continue appropriate antibiotics at least for the duration of neutropenia (until ANC >500 cells/mm³) 2
• For complicated UTIs: 7-14 days of therapy 1
• Monitor for clinical response and adjust therapy based on culture results and susceptibility testing

The evidence strongly supports using carbapenems for susceptible Klebsiella and newer agents like ceftazidime-avibactam for carbapenem-resistant strains, with treatment decisions guided by resistance mechanisms and infection severity.