What are the recommended doses of antibiotics for treating typhoid fever?

Recommended Antibiotic Doses for Treating Typhoid Fever

The first-line treatment for typhoid fever is oral ciprofloxacin 15 mg/kg twice daily for 7-10 days or azithromycin 20 mg/kg once daily for 5-7 days, with treatment selection based on local resistance patterns. 1

First-Line Treatment Options

Oral Therapy

• Ciprofloxacin: 15 mg/kg twice daily for 7-10 days 1
  • Adult dose: 500 mg twice daily for 10 days 2
• Azithromycin: 20 mg/kg once daily for 5-7 days 1
  • Adult dose: 500 mg once daily for 7 days 3, 4
  • Particularly effective against quinolone-resistant strains 3, 4

Parenteral Therapy (for severe cases)

• Ceftriaxone: 80 mg/kg daily for 5-7 days 1
  • Adult dose: 2g IV daily for 14 days 5

Treatment Selection Based on Resistance Patterns

For Fully Susceptible S. typhi

• Fluoroquinolones (ciprofloxacin or ofloxacin) are effective 4

For Quinolone-Resistant S. typhi

• Azithromycin is the preferred treatment 3, 4
  • Lower risk of clinical failure (OR 0.48) compared to fluoroquinolones 3
  • Lower risk of relapse (OR 0.09) compared to ceftriaxone 3
• Ceftriaxone or cefixime as alternatives 4

For Multidrug-Resistant S. typhi

• In areas with high fluoroquinolone resistance (>70% in South Asia), avoid fluoroquinolones as first-line therapy 5
• Azithromycin is recommended as first-line treatment 3, 4

Treatment Duration

• Ciprofloxacin: 7-10 days 1, 2
• Azithromycin: 5-7 days (standard) or 7 days (for complicated cases) 1, 3
• Ceftriaxone: 5-7 days 1

Special Considerations

• For severe cases requiring hospitalization, consider starting with IV ceftriaxone before transitioning to oral therapy when clinically improved 4
• Fever typically clears within 4-5 days of appropriate therapy 4
• Azithromycin has superior efficacy in areas with high fluoroquinolone resistance 3
• Short-course ciprofloxacin (7 days) has shown 96% cure rates in adult patients with rapid defervescence (median: 4 days) 6

Treatment Failure Management

• If poor response to initial therapy, consider:
  • Confirming antimicrobial susceptibility testing 4
  • Switching to a third-generation cephalosporin (e.g., ceftriaxone) 4
  • Combination therapy may be necessary in complicated cases 4

Common Pitfalls to Avoid

• Using ciprofloxacin empirically for cases originating from South Asia due to high resistance rates 5, 4
• Relying solely on ciprofloxacin disc testing for determining fluoroquinolone sensitivity; the organism should also be sensitive to nalidixic acid 5
• Underdosing azithromycin - studies show that 500 mg daily may provide suboptimal systemic exposure for eliminating extracellular circulating S. typhi 7
• Stopping treatment prematurely - complete the full course to prevent relapse 2