From the Guidelines
Antibiotics effective against Pseudomonas aeruginosa include antipseudomonal penicillins, such as piperacillin-tazobactam, and cephalosporins, such as ceftazidime or cefepime, which should be used in combination with other agents like aminoglycosides or fluoroquinolones for serious infections. The most recent and highest quality study, published in 2022 1, recommends treatment options for infections due to carbapenem-resistant Pseudomonas aeruginosa (CRPA) and difficult-to-treat Pseudomonas aeruginosa (DTR-PA), including piperacillin-tazobactam, ceftazidime, cefepime, and ciprofloxacin, with durations of 5-14 days.
- Key considerations for treatment include:
- Using antipseudomonal beta-lactams, such as piperacillin-tazobactam, ceftazidime, or cefepime, in combination with aminoglycosides or fluoroquinolones for serious infections
- Adjusting dosing for patients with renal impairment
- Obtaining cultures and susceptibility testing to guide definitive therapy
- Considering local antibiograms to inform empiric choices, as resistance patterns vary geographically
- Using higher doses and extended or continuous infusions of beta-lactams for severe infections to maximize time above minimum inhibitory concentration. Other studies, such as those published in 2007 1, 2009 1, and 2021 1, also support the use of combination therapy for serious Pseudomonas infections, but the 2022 study 1 provides the most recent and comprehensive guidelines. The recommended treatment duration is 5-14 days, depending on the infection site and severity, and definitive treatment durations should be individualized according to infection sites, source control, underlying comorbidities, and initial response to therapy.
From the FDA Drug Label
Levofloxacin has in vitro activity against Gram-negative and Gram-positive bacteria: Gram-Negative Bacteria Pseudomonas aeruginosa
Gentamicin has been shown to be active against most of the following bacteria, both in vitro and in clinical infections: Gram-Negative Bacteria Pseudomonas aeruginosa
Antibiotics for pseudomonas coverage include:
- Levofloxacin: has in vitro activity against Pseudomonas aeruginosa 2
- Gentamicin: has been shown to be active against Pseudomonas aeruginosa 3
From the Research
Antibiotics for Pseudomonas Coverage
- The choice of antibiotic for Pseudomonas coverage depends on various factors, including the severity of the infection, the patient's medical history, and the local epidemiology of antibiotic resistance 4.
- Piperacillin/tazobactam is an option for treating severe Pseudomonas aeruginosa infections, especially when the minimum inhibitory concentration (MIC) is low 5.
- Ceftolozane-tazobactam and ceftazidime-avibactam are recommended as empirical treatments for suspected Pseudomonas aeruginosa infections, especially in areas with high rates of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains 4.
- A systematic review and meta-analysis found no difference in all-cause mortality between different antibiotic monotherapies for severe Pseudomonas aeruginosa infections, but noted higher clinical failure rates with carbapenems compared to piperacillin-tazobactam for pneumonia 6.
- Combination therapy with a beta-lactam and an aminoglycoside or fluoroquinolone may be effective against Pseudomonas aeruginosa, with piperacillin/tazobactam plus an aminoglycoside resulting in the highest susceptibility rate (93.3%) in one study 7, 8.
- Local institutional use of combination antibiograms may help optimize empirical therapy for infections caused by difficult-to-treat pathogens like Pseudomonas aeruginosa 8.
Specific Antibiotic Options
- Imipenem is considered one of the most effective clinical drugs for treating Pseudomonas aeruginosa infections, but resistance to imipenem is a growing concern 5, 4.
- Cefepime, piperacillin/tazobactam, gentamicin, ciprofloxacin, and levofloxacin are other antibiotics that have been studied for their effectiveness against Pseudomonas aeruginosa 7.
- Newer antibiotics like cefiderocol and imipenem-cilastatin-relebactam may be effective against MDR and XDR Pseudomonas aeruginosa strains, but their use should be reserved for cases where other options are not effective 4.
Considerations for Antibiotic Choice
- The choice of antibiotic should be guided by the results of antimicrobial susceptibility testing, when available 5, 4.
- The patient's medical history, including any previous antibiotic use or allergies, should be taken into account when selecting an antibiotic 4.
- Local epidemiology and resistance patterns should also be considered when choosing an antibiotic for Pseudomonas coverage 4, 8.