What are the recommended cephalosporins (antibiotics) with Pseudomonas coverage?

Cephalosporins with Pseudomonas Coverage

Ceftazidime and cefepime are the only cephalosporins with reliable antipseudomonal activity, with ceftazidime being the most active cephalosporin against Pseudomonas aeruginosa. 1, 2

Primary Antipseudomonal Cephalosporins

Ceftazidime

• Dosage: 2g IV every 8 hours 1, 2
• Indications: FDA-approved for various Pseudomonas infections including:
  • Lower respiratory tract infections
  • Skin and skin-structure infections
  • Urinary tract infections
  • Bacterial septicemia
  • Bone and joint infections 2
• Efficacy: Excellent activity against gram-negative bacilli, including P. aeruginosa 3
• Clinical evidence: Demonstrated effectiveness against multiresistant Pseudomonas with 72% bacteriological response rate 4

Cefepime

• Dosage: 1-2g IV every 8-12 hours (use 2g every 8 hours for Pseudomonas infections) 5
• Indications: FDA-approved for:
  • Moderate to severe pneumonia due to P. aeruginosa
  • Empiric therapy for febrile neutropenic patients
  • Complicated intra-abdominal infections (in combination with metronidazole) 5
• Efficacy: Broad-spectrum coverage similar to ceftazidime with good antipseudomonal activity 6

Clinical Applications

Hospital-Acquired and Ventilator-Associated Pneumonia

For empiric treatment of HAP/VAP where Pseudomonas is suspected:

• Use an antipseudomonal cephalosporin (cefepime or ceftazidime) 1
• Consider combination therapy with either:
  • An aminoglycoside (amikacin, gentamicin, or tobramycin)
  • OR an antipseudomonal fluoroquinolone (ciprofloxacin or levofloxacin) 1, 6

Intra-abdominal Infections

• For severe intra-abdominal infections with suspected Pseudomonas:
  • Cefepime 2g IV every 8-12 hours plus metronidazole 1
  • Alternative: piperacillin-tazobactam or carbapenems 1

Urinary Tract Infections

• For severe UTIs with suspected Pseudomonas:
  • Ceftazidime 2g IV every 8 hours
  • Cefepime 2g IV every 12 hours 6, 5

Important Clinical Considerations

Resistance Concerns

• Local antibiograms should guide therapy as resistance patterns vary by institution 6
• Empiric regimens should be informed by local distribution of pathogens and their susceptibilities 1
• Resistance can develop during therapy, particularly in cystic fibrosis patients 4, 7

Combination Therapy

• For serious Pseudomonas infections, combination therapy is often recommended:
  • Antipseudomonal β-lactam (ceftazidime or cefepime) plus either:
    • Aminoglycoside (amikacin, gentamicin, tobramycin)
    • OR fluoroquinolone (ciprofloxacin, levofloxacin) 1, 6
  • This approach increases the likelihood of appropriate initial coverage and may prevent resistance development 1, 6

Limitations

• Other cephalosporins like ceftriaxone have insufficient activity against P. aeruginosa and should not be used as monotherapy for suspected pseudomonal infections 8, 9
• Ceftriaxone would require combination with an aminoglycoside or antipseudomonal penicillin if Pseudomonas is suspected 9

Dosing Adjustments

• Renal dose adjustments are necessary for both ceftazidime and cefepime in patients with impaired renal function 5
• Extended infusions may be appropriate to optimize pharmacokinetic/pharmacodynamic parameters 1

Remember that appropriate initial antimicrobial therapy is crucial, as delays in administering appropriate therapy have been associated with increased mortality in serious infections 1. Always consider local resistance patterns when selecting antipseudomonal therapy.