What are the recommended antibiotics for treating complicated cystitis?

Recommended Antibiotics for Complicated Cystitis

For patients with complicated cystitis, fluoroquinolones are the most appropriate first-line treatment, with ciprofloxacin 500mg twice daily for 7 days being the preferred option when local resistance rates are below 10%. 1

First-Line Treatment Options

• For outpatient treatment where fluoroquinolone resistance is <10%:

  • Ciprofloxacin 500mg twice daily for 7 days 1
  • Extended-release ciprofloxacin 1000mg once daily for 7 days 1
  • Levofloxacin 750mg once daily for 5 days 1

• When fluoroquinolone resistance is >10%, add an initial one-time parenteral dose of:

  • Ceftriaxone 1g IV 1 OR
  • A consolidated 24-hour dose of an aminoglycoside 1

Alternative Treatment Options

• Trimethoprim-sulfamethoxazole (160/800mg twice daily for 14 days) is appropriate only when the uropathogen is known to be susceptible 1

  • If susceptibility is unknown, combine with an initial IV dose of ceftriaxone 1g or aminoglycoside 1

• Oral β-lactams are less effective than other agents for complicated UTIs 1

  • If used, should be combined with an initial IV dose of ceftriaxone 1g or aminoglycoside 1
  • Treatment duration should be 10-14 days when using β-lactams 1

For Hospitalized Patients

• Initial IV antimicrobial regimen options include: 1
  • Fluoroquinolone
  • Aminoglycoside with or without ampicillin
  • Extended-spectrum cephalosporin or extended-spectrum penicillin (with or without aminoglycoside)
  • Carbapenem

Important Clinical Considerations

• Always obtain urine culture and susceptibility testing in complicated cystitis to guide therapy 1
• Tailor initial empiric therapy based on local resistance patterns 1
• Adjust therapy based on culture results when available 1
• For patients with structural or functional abnormalities of the urinary tract, longer treatment durations are typically required compared to uncomplicated cystitis 1

Common Pitfalls to Avoid

• Using fluoroquinolones empirically when local resistance rates exceed 10% without adding an initial parenteral antibiotic 1
• Using trimethoprim-sulfamethoxazole empirically without knowledge of susceptibility patterns 1
• Using amoxicillin or ampicillin as empiric therapy due to poor efficacy and high resistance rates 1
• Failing to obtain cultures in complicated UTIs, which is essential for guiding appropriate therapy 1
• Using oral β-lactams as monotherapy without an initial parenteral dose, as they have inferior efficacy in complicated UTIs 1

Treatment Algorithm

1. Assess severity and need for hospitalization
2. Obtain urine culture and susceptibility testing
3. Select empiric therapy based on local resistance patterns:
   • If fluoroquinolone resistance <10%: Ciprofloxacin or levofloxacin
   • If fluoroquinolone resistance >10%: Fluoroquinolone plus initial parenteral antibiotic
4. Adjust therapy based on culture results
5. Complete appropriate duration of therapy (7 days for fluoroquinolones, 14 days for TMP-SMX)