If a patient is on intravenous (IV) antibiotics for osteomyelitis and develops Clostridioides difficile (C. diff) infection, should I continue the IV antibiotics and start oral vancomycin?

Management of C. difficile Infection in a Patient with Osteomyelitis on IV Antibiotics

Yes, you should continue IV antibiotics for osteomyelitis while starting oral vancomycin for C. difficile infection. 1

Treatment Approach

For C. difficile infection:

• Start oral vancomycin 125 mg four times daily for 10 days 1
• Alternative option: fidaxomicin 200 mg twice daily for 10 days (may have lower recurrence rates) 1
• For severe or fulminant C. difficile infection:
  • Increase vancomycin to 500 mg four times daily 1
  • Consider adding IV metronidazole 500 mg three times daily for fulminant cases 1

For ongoing osteomyelitis treatment:

• Continue IV antibiotics for osteomyelitis to complete the full treatment course (typically 6 weeks) 2
• Do not interrupt the osteomyelitis treatment as this could lead to treatment failure and worse outcomes 2

Rationale and Evidence

1. C. difficile management: Oral vancomycin is the standard treatment for C. difficile infection per IDSA guidelines 1
2. Osteomyelitis treatment: Interrupting antibiotic therapy for osteomyelitis could lead to treatment failure, with failure rates already ranging from 10-30% even with complete treatment 2
3. Concurrent management: The development of C. difficile is a known complication of antibiotic therapy but does not necessitate discontinuation of essential antibiotics for serious infections like osteomyelitis 1

Special Considerations

If patient has difficulty taking oral medications:

• Administer vancomycin via nasogastric tube 1
• For ileus: add rectal vancomycin 500 mg in 100 mL normal saline every 6 hours 1

Monitoring during treatment:

• Monitor for resolution of diarrhea within 3 days of starting vancomycin 1
• Assess renal function, especially in elderly patients 1
• Watch for signs of worsening osteomyelitis (increased pain, fever, inflammatory markers) 2

Prevention of C. difficile Recurrence

• Consider discontinuing any non-essential antibiotics 1
• Review and discontinue unnecessary proton pump inhibitors 1
• For patients with multiple recurrences, consider:
  • Vancomycin taper/pulse regimen 1
  • Bezlotoxumab as adjunctive therapy 1
  • Fecal microbiota transplantation after appropriate antibiotic treatment failures 1, 3

Important Caveats

• Do not stop IV antibiotics for osteomyelitis as this could lead to treatment failure and worse outcomes 2
• If the patient's C. difficile infection is severe or fulminant, surgical consultation may be necessary 1
• The risk of C. difficile recurrence is higher in patients who continue to receive antibiotics for other indications, so close monitoring is essential 1

Alternative Considerations for Osteomyelitis Treatment

• If the current IV antibiotic is particularly high-risk for C. difficile, consider consulting infectious disease to discuss possible alternatives with equivalent efficacy for osteomyelitis 2
• For MRSA osteomyelitis, daptomycin may be considered as an alternative to vancomycin with potentially lower recurrence rates (29% vs 61.7%) 4

Remember that both infections require complete treatment courses, and premature discontinuation of either therapy could lead to worse outcomes.