What is the recommended treatment for bubonic plague?

Treatment of Bubonic Plague

Streptomycin (15 mg/kg IM every 12 hours) or gentamicin (1.5 mg/kg IV every 8 hours) is the first-line treatment for bubonic plague, with doxycycline (100 mg twice daily) as an effective alternative. 1, 2

First-Line Treatment Options

Aminoglycosides

• Streptomycin: 15 mg/kg IM every 12 hours (adjust for renal function)
• Gentamicin: 1.5 mg/kg IV every 8 hours or 4.5-7.5 mg/kg IV/IM every 24 hours
  • Gentamicin can be substituted when streptomycin is unavailable 1
  • Monitoring of drug levels is necessary to prevent toxicity 2

Tetracyclines

• Doxycycline: 100 mg PO/IV twice daily 1
  • Highly effective with 95-98% survival rates in bubonic plague 1

Fluoroquinolones

• Ciprofloxacin: 400 mg IV every 8-12 hours or 500 mg PO every 8-12 hours 2
• Levofloxacin: 500-750 mg IV/PO every 24 hours 2, 3
  • 100% survival rate reported with fluoroquinolone monotherapy for bubonic plague 1

Treatment Approach Based on Clinical Presentation

Uncomplicated Bubonic Plague

• For stable patients with primary bubonic plague without signs of septicemia or pneumonia:
  • Monotherapy with any first-line agent is acceptable 1, 2
  • Treatment duration: 10-14 days 1, 2

Severe or Complicated Bubonic Plague

• For patients with large buboes or signs of progression to septicemic/pneumonic plague:
  • Consider dual therapy with two different antimicrobial classes 1, 2
  • Preferred combination: fluoroquinolone plus aminoglycoside 2
  • Surgical drainage may be necessary for suppurative buboes 1

Secondary Plague Meningitis

• If meningitis is suspected (e.g., nuchal rigidity):
  • Dual therapy with chloramphenicol plus moxifloxacin or levofloxacin 1
  • If chloramphenicol unavailable, use moxifloxacin or levofloxacin 1

Special Populations

Pediatric Patients

• Gentamicin: 4.5-7.5 mg/kg IV/IM every 24 hours 2
• Ciprofloxacin: 10 mg/kg IV every 8-12 hours or 15 mg/kg PO every 8-12 hours (not exceeding adult dose) 2
• Doxycycline: For children <8 years, use only when other options exhausted due to dental staining risk 1, 2

Pregnant Women

• Fluoroquinolones remain first-line despite pregnancy 2
• Gentamicin is an acceptable alternative with appropriate monitoring 2

Monitoring and Precautions

• Patients should be placed in respiratory isolation for 48 hours after starting effective therapy to prevent secondary pneumonic plague transmission 1
• Monitor for clinical improvement within 48-72 hours of treatment initiation
• Aminoglycoside levels should be monitored to prevent toxicity 2
• Early treatment is critical - mortality increases significantly with delays beyond 24 hours 4

Treatment Efficacy Data

• Survival rates with appropriate treatment 1, 5:
  • Aminoglycosides: 83-91% survival
  • Tetracyclines: 95-98% survival
  • Fluoroquinolones: 100% survival (limited data)
• Overall mortality with high-efficacy antimicrobials is 9% compared to 51% with limited-efficacy antibiotics 5

Common Pitfalls to Avoid

1. Delayed recognition and treatment (mortality increases significantly)
2. Using beta-lactam antibiotics as monotherapy (poor efficacy against Y. pestis)
3. Failure to consider plague in endemic areas or with relevant exposure history
4. Inadequate duration of treatment (should be 10-14 days)
5. Failure to implement appropriate isolation precautions

Early recognition and prompt initiation of appropriate antibiotic therapy are the most critical factors in improving survival of bubonic plague.