What antibiotics are used to treat infected centipede bites?

Antibiotics for Infected Centipede Bites

Amoxicillin-clavulanate is the first-line antibiotic treatment for infected centipede bites, with alternatives including doxycycline, clindamycin, or trimethoprim-sulfamethoxazole for penicillin-allergic patients. 1

Clinical Presentation and Diagnosis

• Infected centipede bites typically present with:
  • Progressive pain beyond 24-48 hours
  • Increasing erythema and swelling
  • Warmth and tenderness extending beyond the initial bite area
  • Purulent discharge
  • Systemic symptoms (fever, chills)

Antibiotic Selection

First-line Treatment (Oral):

• Amoxicillin-clavulanate 875/125 mg twice daily 1
  • Provides coverage against both aerobic and anaerobic bacteria commonly found in bite wounds

Alternative Oral Options (for penicillin-allergic patients):

• Doxycycline 100 mg twice daily 1
  • Excellent activity against Pasteurella species
• Clindamycin 300-400 mg three times daily 1
  • Good activity against staphylococci, streptococci, and anaerobes
• Trimethoprim-sulfamethoxazole 160-800 mg twice daily 1
  • Consider adding metronidazole for anaerobic coverage

For Severe Infections (Intravenous):

• Ampicillin-sulbactam 1.5-3.0 g every 6-8 hours 1
• Piperacillin-tazobactam 3.37 g every 6-8 hours 1
• Carbapenems (ertapenem, imipenem, meropenem) 1

Special Considerations

MRSA Coverage

• Consider MRSA coverage if:
  • Local prevalence is high
  • Previous MRSA infection
  • Failure of initial therapy
• Options for MRSA coverage:
  • Trimethoprim-sulfamethoxazole 1, 2
  • Doxycycline 1
  • Linezolid or vancomycin for severe infections 1

Duration of Treatment

• Uncomplicated infections: 5-7 days
• Complicated infections (deeper tissue involvement): 10-14 days
• Osteomyelitis or septic arthritis: 4-6 weeks 1

Wound Management

• Thorough wound cleansing with sterile normal saline 1
• Remove any foreign bodies or debris
• Consider debridement for necrotic tissue 3
• Elevate the affected limb to reduce swelling 1

When to Consider Prophylactic Antibiotics

A randomized controlled trial specifically studying centipede bites found that prophylactic antibiotics (dicloxacillin) did not significantly reduce infection rates compared to placebo 4. However, preemptive antibiotic therapy (3-5 days) should be considered for patients who:

• Are immunocompromised
• Are asplenic
• Have advanced liver disease
• Have preexisting or resultant edema of the affected area
• Have moderate to severe injuries, especially to the hand or face 1

Clinical Course and Follow-up

• Most centipede bites have benign outcomes with appropriate treatment 5, 6
• Rare complications include:
  • Necrotizing fasciitis 3
  • Anaphylaxis (5% of cases) 5
  • Secondary bacterial infections

Key Pitfalls to Avoid

1. Delaying treatment for severe or progressive infections
2. Failing to consider MRSA in non-responsive infections 2
3. Inadequate wound care which can lead to complications regardless of antibiotic therapy
4. Using first-generation cephalosporins alone (e.g., cephalexin) or penicillinase-resistant penicillins (e.g., dicloxacillin) without additional coverage for potential pathogens 1

Monitor patients closely for signs of progressive infection, and adjust antibiotic therapy based on clinical response and culture results when available.