What is the best treatment for a patient with a urine culture positive for Pseudomonas (Pseudomonas aeruginosa) and Enterococcus (Enterococcus faecalis) and a penicillin (PCN) allergy?

From the Guidelines

For a patient with a urine culture positive for both Pseudomonas aeruginosa and Enterococcus faecalis who has a penicillin allergy, the recommended treatment would be ciprofloxacin 400 mg IV q8h, as it is effective against Pseudomonas aeruginosa and has some activity against Enterococcus faecalis, and is a recommended option for urinary tract infections due to its high concentration in urine 1. When considering the treatment for such infections, it's crucial to prioritize the coverage of both pathogens while taking into account the patient's allergy to penicillin.

• The treatment options for Pseudomonas aeruginosa, especially in the context of urinary tract infections, include antipseudomonal penicillins, cephalosporins, fluoroquinolones like ciprofloxacin, and aminoglycosides, with the choice depending on susceptibility patterns and the severity of the infection 1.
• For Enterococcus faecalis, particularly in a patient with a penicillin allergy, alternatives to penicillin such as vancomycin are considered, but given the context of a urinary tract infection and the presence of Pseudomonas, ciprofloxacin's broad-spectrum activity makes it a viable option for covering both pathogens in some cases.
• The duration of treatment should be individualized based on the severity of the infection, the patient's response to therapy, and whether the infection is complicated or uncomplicated, with general guidelines suggesting 5-10 days for uncomplicated urinary tract infections and 10-14 days for more complicated cases 1.
• It's also important to note that the treatment should be guided by antimicrobial susceptibility testing results whenever possible, to ensure the chosen antibiotic is effective against the specific strains of Pseudomonas aeruginosa and Enterococcus faecalis isolated from the patient 1.

From the FDA Drug Label

1. 10 Complicated Urinary Tract Infections: 10-day Treatment Regimen Levofloxacin tablets are indicated in adult patients 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)].

The best treatment for a patient with a urine culture positive for Pseudomonas aeruginosa and Enterococcus faecalis and a penicillin (PCN) allergy is levofloxacin.

• Key points:
  • Levofloxacin is indicated for the treatment of complicated urinary tract infections due to Pseudomonas aeruginosa and Enterococcus faecalis.
  • The recommended treatment regimen is a 10-day course of levofloxacin tablets.
  • It is essential to note that levofloxacin should only be used when the benefit outweighs the risk, and alternative treatment options should be considered in patients with a penicillin allergy 2.
• Important consideration: The patient's penicillin allergy should be taken into account when selecting an antibiotic, and levofloxacin is a suitable alternative in this case 2.

From the Research

Treatment Options for Pseudomonas aeruginosa and Enterococcus faecalis Urine Culture with Penicillin Allergy

• The patient has a urine culture positive for Pseudomonas aeruginosa and Enterococcus faecalis, and a penicillin allergy, which limits treatment options 3, 4.
• Ciprofloxacin has been shown to be effective in treating Pseudomonas aeruginosa urinary tract infections, with a cure rate of 64% at one month follow-up 3.
• However, the use of ciprofloxacin may be limited due to resistance, and alternative options such as gatifloxacin may be considered 5.
• Gatifloxacin has been shown to have bactericidal activity against Pseudomonas aeruginosa and Enterococcus faecalis in an in vitro bladder model, with a presumed breakpoint MIC of 16-32 microg/ml 5.
• Other treatment options for urinary tract infections caused by multidrug-resistant Pseudomonas spp. include ceftazidime, cefepime, piperacillin-tazobactam, carbapenems, and fosfomycin 4.
• It is essential to use antimicrobials wisely to avoid resistance development, and to consider local susceptibility patterns and the patient's specific condition when selecting a treatment option 4.

Considerations for Treatment

• The patient's penicillin allergy must be taken into account when selecting a treatment option, and alternative antibiotics such as fluoroquinolones or carbapenems may be considered 4.
• The use of ciprofloxacin or other fluoroquinolones may be limited due to resistance, and alternative options such as gatifloxacin or other antibiotics may be necessary 3, 5.
• The treatment option selected should be based on the patient's specific condition, the susceptibility of the infecting organisms, and the potential for resistance development 4.