What is the best oral (PO) antibiotic to use when stepping down from intravenous (IV) ceftriaxone for infected urolithiasis after the stone has passed?

From the Guidelines

For stepping down from IV ceftriaxone in treated urolithiasis after stone passage, oral ciprofloxacin 500 mg twice daily for 7-14 days is typically the best option. This recommendation is based on the guidelines provided by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases, as outlined in the study published in Clinical Infectious Diseases 1. The choice of antibiotic should be guided by urine culture results and local resistance patterns. Ciprofloxacin is preferred due to its excellent urinary tract penetration, broad coverage against common urinary pathogens, including gram-negative organisms like E. coli, and similar coverage to ceftriaxone.

Some key points to consider when selecting an antibiotic for this condition include:

• The prevalence of fluoroquinolone resistance in the community, which should not exceed 10% for ciprofloxacin to be an appropriate choice 1
• The use of an initial intravenous dose of a long-acting parenteral antimicrobial, such as 1 g of ceftriaxone, if the prevalence of fluoroquinolone resistance is thought to exceed 10% 1
• The importance of completing the full antibiotic course, even after symptoms resolve, to ensure complete eradication of the infection
• The need for adequate hydration (2-3 liters daily) to prevent stone recurrence and consideration of straining urine to capture any additional stone fragments for analysis
• Follow-up with urinalysis after treatment completion to confirm resolution of infection, and prompt reevaluation if symptoms worsen or fever returns, as this may indicate persistent infection or additional stone fragments.

Alternatives to ciprofloxacin may include trimethoprim-sulfamethoxazole (TMP-SMX) DS twice daily or amoxicillin-clavulanate 875/125 mg twice daily for the same duration, but these should be chosen based on specific patient factors, such as allergy history and local resistance patterns 1.

From the FDA Drug Label

14 CLINICAL STUDIES

Adult inpatients and outpatients with a diagnosis of community-acquired bacterial pneumonia were evaluated in 2 pivotal clinical studies In the first study, 590 patients were enrolled in a prospective, multicenter, unblinded randomized trial comparing levofloxacin 500 mg once daily orally or intravenously for 7 to 14 days to ceftriaxone 1 to 2 grams intravenously once or in equally divided doses twice daily followed by cefuroxime axetil 500 mg orally twice daily for a total of 7 to 14 days

The best PO antibiotic to use when stepping down from IV ceftriaxone for infected urolithiasis now that the stone has passed is levofloxacin (PO), as it has been shown to be effective in treating various bacterial infections, including those caused by gram-negative bacteria, which are commonly associated with urinary tract infections.

• Key points:
  • Levofloxacin has a broad spectrum of activity against both gram-positive and gram-negative bacteria.
  • It has been evaluated in several clinical studies for the treatment of various infections, including community-acquired pneumonia and acute bacterial sinusitis.
  • The recommended dose of levofloxacin for the treatment of complicated urinary tract infections or pyelonephritis is 250 mg or 500 mg orally or intravenously once daily for 10 to 14 days, although this information is not present in the provided label, the label does provide information on the efficacy of levofloxacin in other infections 2

From the Research

PO Antibiotic Options for Infected Urolithiasis

When stepping down from IV ceftriaxone for infected urolithiasis after the stone has passed, the choice of oral antibiotic is crucial. The following options are considered:

• Nitrofurantoin: effective against ESBL-E coli and ESBL-Klebsiella pneumoniae 3
• Fosfomycin: effective against ESBL-E coli, ESBL-Klebsiella pneumoniae, and carbapenem-resistant Enterobacteriales (CRE) 3
• Pivmecillinam: effective against ESBL-E coli and ESBL-Klebsiella pneumoniae 3
• Amoxicillin-clavulanate: less effective than ciprofloxacin for uncomplicated cystitis, but can be considered for step-down therapy 4
• Fluoroquinolones (e.g., ciprofloxacin): effective against various uropathogens, including ESBL-producing bacteria, but resistance rates may be high in some areas 3, 5

Considerations for Antibiotic Choice

When selecting a PO antibiotic, consider the following factors:

• Local resistance patterns: choose an antibiotic with known activity against the suspected or confirmed uropathogen 3
• Patient factors: consider underlying medical conditions, such as immunocompromised status or anatomical anomalies, which may increase the risk of infection or treatment failure 5
• Stone characteristics: infection stones or stones causing obstructive pyelonephritis may require more aggressive antibiotic therapy 6

Duration of Antibiotic Therapy

The duration of antibiotic therapy should be determined based on the individual patient's needs and the type of surgery or procedure performed. In general, antibiotic prophylaxis should be limited to a short duration, and therapy should be tailored to the specific uropathogen and patient factors 7, 5