From the Guidelines
To cover Pseudomonas aeruginosa when using vancomycin, an antipseudomonal agent such as piperacillin-tazobactam, cefepime, ceftazidime, meropenem, imipenem-cilastatin, doripenem, aztreonam, or ciprofloxacin should be added. When considering the addition of an antibiotic to vancomycin to cover Pseudomonas aeruginosa, it's crucial to choose an agent with proven efficacy against this pathogen.
- Piperacillin-tazobactam (4.5g IV every 6-8 hours) or cefepime (2g IV every 8 hours) are commonly chosen first-line options 1.
- Carbapenems like meropenem (1g IV every 8 hours) are also effective but typically reserved for more resistant infections.
- Aminoglycosides such as tobramycin or amikacin can be added in severe infections or when resistance is suspected, though they require monitoring for nephrotoxicity and ototoxicity. The most recent and highest quality study 1 suggests that for late pneumonia or presence of other risk factors for nonfermenting Gram-negative bacilli, a b-lactam active against P. aeruginosa such as ceftazidime, cefepime, or piperacillin-tazobactam should be used, with the option to add an aminoglycoside or fluoroquinolone. Given the potential for morbidity and mortality associated with Pseudomonas infections, and the importance of quality of life in treating such infections effectively, the choice of antipseudomonal agent to add to vancomycin should be guided by the most recent and highest quality evidence available, which currently supports the use of agents like piperacillin-tazobactam or cefepime as first-line options 1.
From the FDA Drug Label
Nosocomial Pneumonia Piperacillin and Tazobactam for Injection is indicated in adults and pediatric patients (2 months of age and older) for the treatment of nosocomial pneumonia (moderate to severe) caused by beta-lactamase producing isolates of Staphylococcus aureus and by piperacillin and tazobactam-susceptible Acinetobacter baumannii, Haemophilus influenzae, Klebsiella pneumoniae, and Pseudomonas aeruginosa (Nosocomial pneumonia caused by P. aeruginosa should be treated in combination with an aminoglycoside) Initial presumptive treatment of adult patients with nosocomial pneumonia should start with piperacillin and tazobactam for injection at a dosage of 4. 5 grams every six hours plus an aminoglycoside,
To cover Pseudomonas aeruginosa, piperacillin-tazobactam should be added to vancomycin, and it is recommended to use it in combination with an aminoglycoside 2.
- Piperacillin-tazobactam is effective against Pseudomonas aeruginosa.
- Aminoglycoside should be used in combination for the treatment of nosocomial pneumonia caused by P. aeruginosa.
From the Research
Antibiotic Options to Cover Pseudomonas Aeruginosa
To cover Pseudomonas aeruginosa when using vancomycin, several antibiotic options can be considered:
- Aminoglycosides (such as gentamicin, tobramycin, or amikacin) in combination with a beta-lactam antibiotic 3
- Beta-lactam antibiotics with antipseudomonal activity, such as piperacillin/tazobactam, ceftazidime, or carbapenems (e.g., meropenem) 4, 5
- Fluoroquinolones (e.g., ciprofloxacin or levofloxacin) in combination with a beta-lactam antibiotic, although the synergy may be comparable to that of aminoglycosides and beta-lactams 6
Considerations for Combination Therapy
When choosing a combination therapy, it is essential to consider the potential for nephrotoxicity, as the combination of vancomycin and piperacillin/tazobactam has been associated with an increased risk of acute kidney injury 7. The selection of antibiotics should be based on the susceptibility pattern of the Pseudomonas aeruginosa isolate and the patient's clinical condition.
Specific Antibiotic Combinations
Some specific combinations that can be considered include: