What are the antipseudomonal antibiotics?

From the Guidelines

Antipseudomonal antibiotics should be chosen based on the susceptibility of the Pseudomonas aeruginosa isolate, with ceftolozane/tazobactam and ceftazidime/avibactam being first-line options for targeted treatment of difficult-to-treat resistance (DTR-PA) infections, as recommended by the most recent guidelines 1. When selecting antipseudomonal antibiotics, it is crucial to consider the severity of the infection, the patient's underlying health conditions, and the local resistance patterns.

• For infections due to carbapenem-resistant Pseudomonas aeruginosa (CRPA) susceptible to other antimicrobial agents, treatment options include piperacillin-tazobactam, ceftazidime, cefepime, ciprofloxacin, and levofloxacin, with durations ranging from 5 to 14 days 1.
• For difficult-to-treat Pseudomonas aeruginosa (DTR-PA) infections, novel β-lactam agents such as ceftolozane/tazobactam and ceftazidime/avibactam are recommended as first-line options, with imipenem/cilastatin–relebactam and cefiderocol as potential alternatives 1.
• Colistin-based therapy may also be considered for DTR-PA infections, with a loading dose followed by 5mg/kg/day IV divided q8-12h 1.
• Treatment duration typically ranges from 7-14 days depending on infection site and severity, and local antibiograms should guide therapy as resistance patterns vary geographically 1.
• Dosing adjustments are necessary for patients with renal impairment, and combination therapy with two antipseudomonal agents from different classes may be recommended initially for patients with sepsis, immunocompromise, or in areas with high resistance rates.

From the FDA Drug Label

Levofloxacin tablets are indicated for the treatment of nosocomial pneumonia due to methicillin-susceptible Staphylococcus aureus, Pseudomonas aeruginosa, Serratia marcescens, Escherichia coli, Klebsiella pneumoniae, Haemophilus influenzae, or Streptococcus pneumoniae. Where Pseudomonas aeruginosa is a documented or presumptive pathogen, combination therapy with an anti-pseudomonal β-lactam is recommended [see Clinical Studies (14.1)]. Levofloxacin tablets are indicated for the treatment of complicated urinary tract infections (mild to moderate) due to Enterococcus faecalis, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, or Pseudomonas aeruginosa [see Clinical Studies (14.8)].

Levofloxacin is an antipseudomonal antibiotic. It is indicated for the treatment of infections caused by Pseudomonas aeruginosa, including:

• Nosocomial pneumonia
• Complicated urinary tract infections However, when Pseudomonas aeruginosa is a documented or presumptive pathogen, combination therapy with an anti-pseudomonal β-lactam is recommended 2.

From the Research

Antipseudomonal Antibiotics

• The following antibiotics have been identified as effective against Pseudomonas aeruginosa:
  • Ceftolozane-tazobactam 3
  • Ceftazidime-avibactam 3
  • Cefiderocol 3, 4
  • Ceftazidime 5
  • Carbapenems 5
  • Piperacillin-tazobactam 5, 6
  • Cefepime 6
  • Gentamicin 6
  • Ciprofloxacin 6
  • Levofloxacin 6

Combination Therapy

• Combination therapy is only recommended in limited scenarios 4
• The use of a beta-lactam plus an aminoglycoside is the standard for treating severe Pseudomonas aeruginosa infections 6
• The combination of a beta-lactam with a fluoroquinolone has been shown to be comparable to the combination of a beta-lactam with an aminoglycoside in terms of synergy 6

Resistance and Treatment Outcomes

• The emergence of multiresistant phenotypes to antipseudomonal antibiotics is a significant concern 7
• The use of carbapenems has been associated with higher rates of resistant P. aeruginosa 5
• No significant difference in mortality, clinical, and microbiological outcomes or adverse events was demonstrated between ceftazidime, carbapenems, and piperacillin-tazobactam as definitive treatment of P. aeruginosa bacteremia 5