What antibiotic (ABX) can be given to a patient with pyelonephritis who is allergic to Bactrim (trimethoprim/sulfamethoxazole) and Rocephin (ceftriaxone)?

From the Guidelines

For a patient with pyelonephritis who is allergic to both trimethoprim/sulfamethoxazole (Bactrim) and ceftriaxone (Rocephin), fluoroquinolones such as ciprofloxacin are the recommended alternative, as suggested by the European Association of Urology guidelines on urological infections 1.

Key Considerations

• Ciprofloxacin can be prescribed at 500 mg orally twice daily for 7 days for uncomplicated cases, or 400 mg intravenously every 12 hours for more severe infections requiring hospitalization.
• If the patient cannot tolerate fluoroquinolones or if there are contraindications, alternatives include amoxicillin-clavulanate (875/125 mg orally twice daily for 14 days) or nitrofurantoin (100 mg orally four times daily for 7 days, though this is less preferred for pyelonephritis).
• Before initiating treatment, obtaining a urine culture is essential to guide therapy based on the specific pathogen and its susceptibility, as recommended by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases 1.
• The choice of antibiotic should also consider local resistance patterns, as E. coli (the most common cause of pyelonephritis) has increasing resistance to fluoroquinolones in some regions.
• Patients should complete the full course of antibiotics even if symptoms improve quickly, and should increase fluid intake to help flush bacteria from the urinary tract.

Additional Guidance

• The Dutch Working Party on Antibiotic Policy (SWAB) guideline for the approach to suspected antibiotic allergy suggests that patients with a suspected immediate-type allergy to cephalosporins can receive penicillins with dissimilar side chains, irrespective of severity and time since the index reaction 1.
• The World Health Organization's essential medicines and AWaRe recommendations suggest that fluoroquinolones, such as ciprofloxacin, are a first-choice option for empiric treatment of mild-to-moderate pyelonephritis, if local/national data on antimicrobial resistance patterns allow its use 1.

From the FDA Drug Label

The following in vitro data are available, but their clinical significance is unknown: Levofloxacin exhibits in vitro minimum inhibitory concentrations (MIC values) of 2 mcg/mL or less against most (≥ 90%) isolates of the following microorganisms; however, the safety and effectiveness of levofloxacin in treating clinical infections due to these bacteria have not been established in adequate and well-controlled clinical trials Gram-Negative Bacteria Escherichia coli Klebsiella pneumoniae Proteus mirabilis Pseudomonas aeruginosa

The patient has pyelonephritis and is allergic to Bactrim and Rocephin. Levofloxacin can be considered as an alternative antibiotic for the treatment of pyelonephritis, as it has shown in vitro activity against common urinary pathogens such as Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa 2. However, it is essential to note that the clinical effectiveness of levofloxacin in treating pyelonephritis has not been established in adequate and well-controlled clinical trials.

• Key considerations:
  • Levofloxacin has in vitro activity against common urinary pathogens
  • Clinical effectiveness in treating pyelonephritis has not been established in adequate and well-controlled clinical trials
  • Patient's allergy to Bactrim and Rocephin should be considered when selecting an alternative antibiotic
• Recommended approach:
  • Consult with an infectious disease specialist or a urologist to determine the best course of treatment for the patient
  • Consider obtaining urine culture and sensitivity results to guide antibiotic selection
  • Monitor the patient closely for signs of treatment failure or adverse reactions to the selected antibiotic 2 2

From the Research

Antibiotic Options for Pyelonephritis

Given the patient's allergy to Bactrim (trimethoprim/sulfamethoxazole) and Rocephin (ceftriaxone), alternative antibiotic options must be considered for the treatment of pyelonephritis.

• The patient's allergy to ceftriaxone, a cephalosporin, may suggest a potential allergy to other cephalosporins, but this is not always the case 3.
• Fluoroquinolones, such as levofloxacin or ciprofloxacin, are potential options, but resistance rates may be high, especially in areas with frequent use of these antibiotics 3, 4.
• Other cephalosporins, such as cephalexin or cefdinir, may be considered, as they have shown efficacy in treating pyelonephritis and may have lower resistance rates compared to other antibiotics 5, 6.

Considerations for Antibiotic Choice

When selecting an antibiotic, it is essential to consider the following factors:

• Local resistance patterns: The prevalence of antibiotic-resistant bacteria in the patient's area should be taken into account when choosing an antibiotic 3, 4.
• Patient factors: The patient's medical history, including any previous allergies or adverse reactions to antibiotics, should be considered 3, 5.
• Antibiotic spectrum: The chosen antibiotic should have a spectrum of activity that covers the most likely pathogens causing pyelonephritis, such as Escherichia coli and Klebsiella pneumoniae 3, 7.

Potential Antibiotic Regimens

Based on the available evidence, potential antibiotic regimens for the patient could include:

• A fluoroquinolone, such as levofloxacin or ciprofloxacin, if the patient is not allergic to this class of antibiotics and local resistance rates are not excessively high 3, 4.
• A cephalosporin, such as cephalexin or cefdinir, if the patient is not allergic to this class of antibiotics and local resistance rates are not excessively high 5, 6.
• Other antibiotics, such as amoxicillin-clavulanate or a carbapenem, may also be considered, but their use should be guided by local resistance patterns and patient factors 7, 6.