From the Guidelines
For Pseudomonas aeruginosa infections resistant to Bactrim, the recommended treatment options include ceftolozane/tazobactam, ceftazidime/avibactam, and colistin-based therapy, as these have shown efficacy in treating difficult-to-treat resistance (DTR-PA) infections, as per the latest guidelines 1. When considering treatment options, it's crucial to note that Pseudomonas aeruginosa is inherently resistant to Bactrim due to its efflux pumps and the low permeability of its outer membrane. Therefore, alternative antibiotics are necessary. The choice of antibiotic should ideally be guided by culture and sensitivity testing to ensure effective treatment, as resistance patterns can vary significantly. Local antibiogram data should be consulted when selecting empiric therapy before sensitivity results are available.
Some key treatment options for DTR-PA include:
- Ceftolozane/tazobactam, which has been recommended as a first-line option for targeted treatment 1.
- Ceftazidime/avibactam, another novel β-lactam agent that is considered a first-line option for DTR-PA infections 1.
- Colistin-based therapy, which may be considered in combination with one or more additional agents to which the pathogen displays in vitro susceptibility, especially when other options are limited 1.
- Other potential alternatives include imipenem/cilastatin–relebactam and cefiderocol, though their use may depend on local resistance patterns and specific patient factors 1.
Treatment duration typically ranges from 5 to 14 days, depending on the infection site and severity, as well as the patient's response to therapy 1. It's also important to consider the pharmacodynamics of the chosen antibiotic, especially in critically ill patients or those with renal impairment, to ensure optimal dosing and minimize the risk of toxicity or treatment failure 1.
In cases where combination therapy is considered, the choice of agents should be based on their synergistic effects and the susceptibility pattern of the isolate. However, the evidence for combination therapy over monotherapy is not always clear-cut, and decisions should be made on a case-by-case basis, considering the latest clinical guidelines and expert opinions 1.
From the FDA Drug Label
As with other drugs in this class, some isolates of Pseudomonas aeruginosa may develop resistance fairly rapidly during treatment with levofloxacin tablets Where Pseudomonas aeruginosa is a documented or presumptive pathogen, combination therapy with an anti-pseudomonal β-lactam is recommended [see Clinical Studies (14.1)]. Culture and susceptibility testing performed periodically during therapy will provide information about the continued susceptibility of the pathogens to the antimicrobial agent and also the possible emergence of bacterial resistance. To reduce the development of drug-resistant bacteria and maintain the effectiveness of levofloxacin tablets and other antibacterial drugs, levofloxacin tablets should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria
Treatment options for Pseudomonas aeruginosa infections resistant to Bactrim (Trimethoprim/Sulfamethoxazole):
- Levofloxacin: may be used to treat Pseudomonas aeruginosa infections, but combination therapy with an anti-pseudomonal β-lactam is recommended if Pseudomonas aeruginosa is a documented or presumptive pathogen.
- Ciprofloxacin: may also be used to treat Pseudomonas aeruginosa infections, but as with levofloxacin, some strains may develop resistance fairly rapidly during treatment.
- Combination therapy: with an anti-pseudomonal β-lactam is recommended for the treatment of Pseudomonas aeruginosa infections, especially if the infection is resistant to Bactrim.
From the Research
Treatment Options for Pseudomonas aeruginosa Infections Resistant to Bactrim
- The standard treatment for severe Pseudomonas aeruginosa infections is a beta-lactam plus an aminoglycoside, but fluoroquinolones can be used as an alternative to aminoglycosides 4
- Combination therapy with a beta-lactam and a fluoroquinolone, such as cefepime and ciprofloxacin or levofloxacin, has been shown to be effective against P. aeruginosa 4
- For urinary tract infections (UTIs) caused by multidrug-resistant (MDR) Pseudomonas spp., treatment options include fluoroquinolones, ceftazidime, cefepime, piperacillin-tazobactam, carbapenems, and ceftolozane-tazobactam 5
- Ceftazidime-avibactam, meropenem/vaborbactam, and imipenem/cilastatin-relebactam are also effective against MDR P. aeruginosa infections 5, 6
- Cefiderocol, a new cephalosporin, has shown promising results against P. aeruginosa, including MDR strains 6, 7
- Monotherapy with ceftazidime, carbapenems, or piperacillin-tazobactam can be effective for P. aeruginosa bloodstream infections, but the choice of antibiotic should be guided by susceptibility testing and local epidemiology 8
Antibiotic Combinations and Resistance
- Combination therapy with a beta-lactam and an aminoglycoside or a fluoroquinolone can help to prevent the development of resistance 4
- The use of newer antibiotics, such as ceftazidime-avibactam and cefiderocol, should be reserved for infections caused by MDR P. aeruginosa strains 5, 6
- Antibiotic stewardship is essential to preserve the effectiveness of new antibiotics and prevent the development of resistance 7