What is the recommended treatment for pyelonephritis?

Treatment for Pyelonephritis

For acute pyelonephritis, fluoroquinolones are the preferred first-line treatment with levofloxacin 750 mg once daily for 5 days or ciprofloxacin 500 mg twice daily for 7 days being the most effective options in areas with fluoroquinolone resistance below 10%. 1

Initial Assessment and Management

• Urine culture and susceptibility testing should always be performed before initiating therapy to guide definitive treatment 1
• Initial empirical therapy should be based on local resistance patterns and subsequently adjusted according to culture results 1
• The most common causative organism is Escherichia coli (75-95%), followed by other Enterobacteriaceae such as Proteus mirabilis and Klebsiella pneumoniae 1

Outpatient Treatment Options

• For mild to moderate pyelonephritis in areas with fluoroquinolone resistance <10%:
  • Ciprofloxacin 500 mg orally twice daily for 7 days 1
  • Levofloxacin 750 mg orally once daily for 5 days 1, 2
  • Ciprofloxacin 1000 mg extended-release once daily for 7 days 1
• For areas with fluoroquinolone resistance >10%, administer an initial one-time intravenous dose of a long-acting parenteral antimicrobial (ceftriaxone 1g or aminoglycoside) before starting oral therapy 1, 3
• Trimethoprim-Sulfamethoxazole (TMP-SMX) 160/800 mg twice daily for 14 days is appropriate only if the pathogen is known to be susceptible 1

Inpatient Treatment Options

• For patients requiring hospitalization, initial intravenous antimicrobial regimens include:
  • Fluoroquinolone (e.g., levofloxacin 750 mg IV daily) 3, 1, 4
  • Aminoglycoside with or without ampicillin 3, 1
  • Extended-spectrum cephalosporin (e.g., ceftriaxone 1g IV every 12 hours) 3, 1, 4
  • Extended-spectrum penicillin, with or without aminoglycoside 3, 1
  • Carbapenem 3, 1

Treatment Duration

• Fluoroquinolones: 5-7 days (levofloxacin 750 mg for 5 days; ciprofloxacin 500 mg for 7 days) 1, 2, 5
• TMP-SMX: 14 days 1
• β-lactams: 10-14 days 3, 1

Special Considerations

• In regions with high fluoroquinolone resistance (>10%), ceftriaxone has shown better microbiological response compared to levofloxacin 4
• Recent research has demonstrated that 7-day ciprofloxacin treatment is as effective as 14-day treatment for acute pyelonephritis in women 5
• For pregnant patients with pyelonephritis, hospitalization with initial parenteral therapy is recommended due to elevated risk of severe complications 6
• In elderly patients, monitor closely for adverse effects, particularly with aminoglycosides and fluoroquinolones 1

Common Pitfalls to Avoid

• Failing to obtain urine cultures before initiating antibiotics 1
• Not considering local resistance patterns when selecting empiric therapy 1
• Using fluoroquinolones empirically in areas with >10% resistance without adding an initial dose of a parenteral agent 1
• Using oral β-lactams as monotherapy without an initial parenteral dose 1
• Not adjusting therapy based on culture results 1
• Inadequate treatment duration, especially with β-lactam agents 1
• Lack of imaging in patients who do not respond to appropriate therapy within 48-72 hours 6

Step-Down Therapy

• Once clinical improvement occurs in hospitalized patients, transition to appropriate oral therapy based on culture results 1
• Oral β-lactams can be used for step-down therapy if the pathogen is susceptible, but they are generally less effective than other available agents 1