What antibiotics are used to treat dysentery?

Antibiotics for Dysentery Treatment

For dysentery treatment, ciprofloxacin is the first-line antibiotic of choice, with azithromycin and cefixime as effective alternatives in areas with high fluoroquinolone resistance. 1

First-Line Treatment Options

Shigellosis (Bacterial Dysentery)

• Ciprofloxacin: 500mg twice daily for 3 days (adults) 1, 2
  • Pediatric dosing: 15mg/kg/day divided twice daily 1
  • Despite concerns about adverse effects in children (e.g., arthropathy), ciprofloxacin remains highly effective and appropriate for shigellosis 1
  • Clinical cure rates exceed 85% 3

Alternative First-Line Options (in areas with high ciprofloxacin resistance)

• Azithromycin: 1000mg single dose or 500mg daily for 3 days 1, 4

  • Pediatric dosing: 10mg/kg/day 4
  • Demonstrated 82% clinical success rate in treating shigellosis 5

• Cefixime: Oral third-generation cephalosporin 1

  • Effective against Shigella strains resistant to ciprofloxacin

Treatment Algorithm Based on Clinical Presentation

Mild to Moderate Dysentery

1. Oral rehydration to prevent dehydration
2. Ciprofloxacin 500mg twice daily for 3 days 2
3. Consider adding loperamide (4mg initial dose followed by 2mg after each loose stool, maximum 16mg/day) to reduce duration of symptoms 6
   • Note: Loperamide combined with ciprofloxacin reduced median duration of diarrhea from 42 to 19 hours in patients with Shigella 6

Severe Dysentery

1. Aggressive rehydration (oral or IV depending on severity)
2. Ciprofloxacin 500mg twice daily for 3-5 days 1, 3
3. Consider parenteral ceftriaxone if unable to tolerate oral medications 1

Dysentery in Special Populations

• Children: Ciprofloxacin remains first-line despite concerns about adverse effects 1, 7
• Pregnant women: Azithromycin preferred due to better safety profile 4
• Immunocompromised patients: Consider longer treatment duration (5 days) 4

Regional Considerations

High Fluoroquinolone Resistance Areas

• Asia-Africa: Higher resistance rates to nalidixic acid (33.6%) and ciprofloxacin (5.0%) compared to Europe-America 1
• In these regions, use azithromycin or cefixime as first-line therapy 1, 4

Resource-Limited Settings

• Short-course ciprofloxacin (1g daily for 2 days) has shown similar efficacy to standard 5-day regimens 8
• This approach improves compliance and allows treatment of more patients with limited supplies

Important Clinical Pearls

• Discontinue other antibiotics if possible during treatment to reduce risk of C. difficile infection 1
• Avoid unnecessary PPIs during treatment as they may increase risk of C. difficile infection 1
• Maintain isolation precautions until resolution of diarrhea (formed stool for at least 48 hours) 1
• Hand hygiene with soap and water is essential as alcohol-based sanitizers may not kill C. difficile spores 1
• Stool testing should be performed to identify the causative organism and guide therapy 4

Treatment Efficacy

The WHO-recommended antibiotics (ciprofloxacin, ceftriaxone, and azithromycin) have demonstrated >99% cure rates in clinical studies 7, significantly reducing morbidity and mortality associated with dysentery. Current recommendations have shown to reduce clinical failure rates by 82% (95% CI, 67-99%) 1.

Antimicrobial Resistance Concerns

• Rising resistance to fluoroquinolones necessitates ongoing surveillance and appropriate antibiotic selection
• Resistance rates to ceftriaxone reached 14.2% in Asia-Africa after 2007 1
• Resistance to nalidixic acid and ciprofloxacin in Asia-Africa has progressively increased each year 1
• Resistance rates are generally higher in children than adults 1

By following this evidence-based approach to antibiotic selection for dysentery, clinicians can effectively treat this potentially serious infection while minimizing complications and reducing the risk of antimicrobial resistance.