What are the recommended antibiotics for septic shock?

Recommended Antibiotics for Septic Shock

For septic shock, administer broad-spectrum empiric antimicrobial therapy within one hour of recognition, with combination therapy recommended for initial management using at least two antibiotics of different antimicrobial classes aimed at the most likely pathogens. 1, 2

Initial Antimicrobial Approach

Timing and Administration

• Administer IV antimicrobials within one hour of recognizing septic shock 2, 1
• Obtain appropriate cultures before starting antibiotics, but do not delay antimicrobial therapy beyond 45 minutes 1

Empiric Regimen Selection

Recommended empiric regimens include:

1. For general septic shock:

   • Meropenem 1-2g IV every 8 hours 1
   • Piperacillin-tazobactam 3.375-4.5g IV every 8 hours 1
   • Plus an aminoglycoside (Gentamicin 5-7mg/kg IV daily) or fluoroquinolone 1, 3

2. For specific pathogens:

   • Pseudomonas aeruginosa: Extended-spectrum β-lactam plus either an aminoglycoside or fluoroquinolone 2, 1
   • Streptococcus pneumoniae bacteremia: β-lactam plus macrolide 2, 1
   • Multidrug-resistant organisms: Consider newer agents such as ceftolozane/tazobactam, ceftazidime/avibactam, or meropenem-vaborbactam 1

3. For special populations:

   • Neutropenic patients: Combination empiric therapy 2
   • Immunocompromised patients: Consider broader coverage including antifungals 2, 1

Duration and De-escalation

• Limit combination therapy to no more than 3-5 days 2, 1
• De-escalate therapy once pathogen identification and susceptibilities are established 2, 1
• Reassess antimicrobial regimen daily for potential de-escalation 1
• Typical duration of therapy is 7-10 days 2, 1
• Consider longer courses for:
  • Slow clinical response
  • Undrainable foci of infection
  • Staphylococcus aureus bacteremia
  • Some fungal and viral infections
  • Immunologic deficiencies including neutropenia 2

Source Control

• Identify infection source through prompt imaging studies 1
• Implement source control measures as soon as possible:
  • Drainage of abscesses
  • Debridement of infected necrotic tissue
  • Removal of infected devices
  • Control of contamination sources 1

Common Pitfalls to Avoid

1. Delayed administration of antibiotics beyond one hour of recognition significantly increases mortality 1
2. Inadequate spectrum of coverage, especially in patients with risk factors for resistant organisms 1
3. Failure to de-escalate broad-spectrum combination therapy once culture results are available 1
4. Inadequate source control, such as delayed drainage or debridement 1
5. Inappropriate dosing of antimicrobials, particularly in patients with altered pharmacokinetics (e.g., obesity, burns) 1, 3
6. Continuing antibiotics in patients with severe inflammatory states determined to be of noninfectious origin 2

Antimicrobial Dosing Considerations

• Optimize dosing based on pharmacokinetic/pharmacodynamic principles 2
• For gentamicin in septic shock, consider higher dosing (5-7mg/kg IV daily) with therapeutic drug monitoring 3
• In patients with renal impairment, adjust dosing according to creatinine clearance 3
• For patients with extensive burns or altered pharmacokinetics, measure serum concentrations to guide dosing 3

Early appropriate antimicrobial therapy combined with adequate source control remains the cornerstone of effective septic shock management, with prompt administration within one hour of recognition being critical to reduce mortality.