Introduction

• Factors in selecting appropriate drugs to manage sepsis syndrome:
  • source of infection
  • gram stain
  • immune status
  • bacterial resistance patterns in the community and hospital
• Treatment:
  • gram-negative bacilli:
    • Third or fourth generation cephalosporins
      •  cefotaxime (Claforan)
      •  ceftizoxime (Cefizox)
      •  cefoperazone (Cefobid)
      •  ceftriaxone (Rocephin)
      •  cefepime (Maxipime)
      •  ceftazidime (plus activity against gram-positive cocci)
    • imipenem, meropenem (Merrem IV), aztreonam (Azactan)
  •  Cephalosporins (other than cefoperazone (Cefobid), cefepime (Maxipime), and ceftazidime (Fortax, Taxidime, Tazicef)): limited efficacy against Pseudomonas aeruginosa
  • Pseudomonas aeruginosa: effectively treated with imipenem, meropenem (Merrem IV), and aztreonam (Azactan).
  •  Aztreonam (Azactan): poor activity against gram-positive organisms and anaerobes
• Initial treatment:
  • Life-threatening sepsis and adults:
    • Third or fourth generation cephalosporin
      •  cefotaxime (Claforan)
      •  ceftizoxime (Cefizox)
      •  ceftriaxone (Rocephin)
      •  cefepime (Maxipime)
    • ticarcillin (Ticar)/clavulanic acid
    • piperacillin (Pipracil)/tazobactam
    • imipenem or meropenem (Merrem IV) {each together with aminoglycoside [gentamicin (Garamycin), tobramycin (Nebcin), or amikacin (Amikin)]}
  • If methicillin-resistant staphylococci is a consideration:
    • vancomycin (Vancocin) alone or
    • vancomycin (Vancocin) with gentamicin (Garamycin) and/or rifampin (Rimactane)
  • If bacterial endocarditisis is a consideration (prior to pathogen identification):
    • vancomycin (Vancocin) plus gentamicin (Garamycin)
  • Treatment of intra-abdominal or pelvic infection (likely to involve anaerobes):
    • ticarcillin (Ticar)/clavulanic acid
    • ampicillin (Principen, Omnipen)/sulbactam
    • piperacillin (Pipracil)/tazobactam
    • imipenem
    • meropenem
    • cefoxitin (Mefoxin) or cefotetan (Cefotan){each with or without an aminoglycoside, metronidazole (Flagyl) OR clindamycin (Cleocin) with an aminoglycoside}

Special Cases

• Neutropenic patients with suspected bacteremia
  • Treatment:
    • ceftazidime (Fortax, Taxidime, Tazicef)
    • imipenem
    • meropenem (Merrem IV)
    • cefepime (Maxipime) (in more seriously ill patients, add an aminoglycoside
    • amikacin (Amikin) and ceftriaxone (Rocephin) (single daily doses)
    • piperacillin (Pipracil)/tazobactam plus amikacin
    • Addition of vancomycin (Vancocin): in neutropenic cancer patients with bacteremia due to methicillin (Staphcillin)-resistant staphylococci were some strains of viridans.
• Resistant gram-negative bacilli
  •  Gram-negative bacilli resistant to:
    • aminoglycosides
    • third-generation cephalosporins
    • aztreonam (Azactan)
  • These bacilli susceptible to:
    • imipenem
    • meropenem (Merrem IV)
    • ciprofloxacin (Cipro)
  • Pseudomonas aeruginosa strains resistant gentamicin (Garamycin):
    • Susceptible to:
      • amikacin (Amikin)
      • ceftazidime (Fortax, Taxidime, Tazicef)
      •   cefepime (Maxipime)
      • imipenem
      • meropenem (Merrem IV)
      • ciprofloxacin (Cipro)
      • trovafloxacin
      • aztreonam
      • possibly tobramycin (Nebcin) or netilmicin (Netromycin)
• Multiple antibiotic resistant enterococci
  •  Many strains resistant to:
    • penicillin
    • ampicillin (Principen, Omnipen)
    • gentamicin (Garamycin)
    • streptomycin
    • vancomycin (Vancocin)
  • Susceptible (in vitro, but with variable clinical results) to:
    • chloramphenicol (Chloromycetin)
    • doxycycline (Vibramycin, Doryx)
    • fluoroquinones

  • Urinary tract infection caused by resistant enterococci may respond to ampicillin or amoxicillin, because very high drug concentrations are found in the urine.

• Urinary tract infection (UTI)
  • Diagnosis
  • Acute, uncomplicated UTI: trimethoprim-sulfamethoxazole (Bactrim)(3-day course of treatment)
    • Alternative: fluoroquinone (three-day course of treatment)
    • Alternative (longer treatment):
      •  oral cephalosporin
      •  amoxicillin (Amoxil Polymox)(many urinary pathogens -- resistance to amoxicillin)
      •  fosfomycin (Monurol)(single dose)
  • Repeated UTIs or UTI occurring in the hospital or nursing-home setting:
    •  may be due to antibiotic-resistant gram-negative bacilli
    • Treatment:
      • fluoroquinone
      • oral amoxicillin (Amoxil Polymox)/clavulanic acid
      • oral third-generation cephalosporin (cefixime (Suprax), cefpodoxime (Vantin), ceftibuten) or idanyl ester of carbenicillin
    • in patients hospitalized with UTI:
      • third-generation cephalosporin
      • ticarcillin (Ticar)/clavulanic acid
      • piperacillin (Pipracil)/tazobactam
      • imipenem (occasionally in combination with aminoglycoside)