What is the recommended treatment for pyelonephritis?

Treatment of Pyelonephritis

For patients with pyelonephritis, oral ciprofloxacin (500 mg twice daily) for 7 days is the first-line treatment for outpatients in areas where fluoroquinolone resistance is below 10%, with an initial IV dose of ceftriaxone 1g recommended if local resistance exceeds 10%. 1

Diagnosis and Initial Assessment

• Always obtain a urine culture and susceptibility test before starting antibiotics 1
• Key clinical features:
  • Fever (may be absent early in illness)
  • Flank pain (nearly universal)
  • Positive urinalysis 2
• E. coli is the most common pathogen (75-95% of cases) 1

Treatment Algorithm

Outpatient Management (Uncomplicated Pyelonephritis)

1. First-line therapy (areas with <10% fluoroquinolone resistance):

   • Oral ciprofloxacin 500 mg twice daily for 7 days 1, 3
   • Alternative: Levofloxacin 750 mg once daily for 5 days 1, 4

2. If local fluoroquinolone resistance >10%:

   • Initial IV dose of ceftriaxone 1g OR
   • Consolidated 24-hour dose of an aminoglycoside
   • THEN continue oral fluoroquinolone regimen 1, 2

3. If susceptibility known:

   • Trimethoprim-sulfamethoxazole (160/800 mg twice daily for 14 days) if pathogen is susceptible 1
   • If using trimethoprim-sulfamethoxazole empirically (susceptibility unknown), give initial IV dose of ceftriaxone 1g 1

4. Oral β-lactams:

   • Less effective than other agents for pyelonephritis 1
   • If used, give initial IV dose of ceftriaxone 1g
   • Treatment duration: 10-14 days 1

Inpatient Management (Severe or Complicated Pyelonephritis)

Initial IV antimicrobial regimen options:

• Fluoroquinolone
• Aminoglycoside (with or without ampicillin)
• Extended-spectrum cephalosporin or penicillin (with or without aminoglycoside)
• Carbapenem 1

Important Considerations

Duration of Therapy

• Fluoroquinolones: 5-7 days (ciprofloxacin 500 mg BID for 7 days or levofloxacin 750 mg daily for 5 days) 1, 3
• Trimethoprim-sulfamethoxazole: 14 days 1
• β-lactams: 10-14 days 1

Antimicrobial Resistance

• Monitor local resistance patterns, especially for fluoroquinolones 1, 5
• In France (2011), approximately 10% of community-acquired E. coli UTI isolates were resistant to ciprofloxacin 5
• Hospital resistance rates to fluoroquinolones were around 18% in 2012 in France 5
• Resistance to third-generation cephalosporins is increasing rapidly (1% in 2005 vs 10% in 2012) 5

Follow-up

• Most patients respond to appropriate therapy within 48-72 hours 6
• If no improvement, consider imaging and repeat cultures 6
• For concurrent urinary tract obstruction, urgent decompression is necessary 6

Special Populations

• Pregnant patients: Higher risk of complications; require admission and initial parenteral therapy 6
• Patients with sepsis or risk of multidrug-resistant organisms: Use antibiotics with activity against extended-spectrum beta-lactamase (ESBL) producing organisms 6

Common Pitfalls to Avoid

• Using oral β-lactams as first-line therapy (inferior efficacy) 1
• Using amoxicillin or ampicillin empirically (high resistance rates) 1
• Failing to obtain urine culture before starting antibiotics 1, 2
• Unnecessary imaging in uncomplicated cases that respond to therapy 2, 6
• Using broad-spectrum antibiotics unnecessarily (contributes to resistance) 5

The evidence strongly supports fluoroquinolones as first-line therapy for uncomplicated pyelonephritis, with 7-day ciprofloxacin or 5-day levofloxacin regimens showing excellent efficacy while minimizing antibiotic exposure 1, 3.