What is the oral dosing regimen for vancomycin (Vancomycin) for the treatment of Clostridioides difficile (C. diff) infection?

Oral Vancomycin Dosing for Clostridioides difficile Infection

For Clostridioides difficile infection (CDI), oral vancomycin should be prescribed at 125 mg four times daily for 10 days as the first-line treatment. 1, 2

Dosing Regimen for Oral Vancomycin

Initial CDI Episode:

• Standard dosing: Vancomycin 125 mg orally four times daily for 10 days 1, 2
• This dosage has been shown to be as effective as higher doses (500 mg four times daily) while being more cost-effective 3

Based on Disease Severity:

• Mild to moderate CDI: Vancomycin 125 mg orally four times daily for 10 days 4, 1
• Severe CDI: Vancomycin 125 mg orally four times daily for 10 days 1
• Severe complicated/fulminant CDI: Vancomycin 125 mg orally four times daily, with consideration of adding IV metronidazole and surgical consultation 1

Recurrent CDI:

• First recurrence: Same treatment as initial episode (vancomycin 125 mg four times daily for 10 days) 1
• Multiple recurrences: Consider vancomycin taper/pulse regimen:
  • 125 mg every 6 hours for 1-2 weeks
  • Then 125 mg every 24 hours for 1 week
  • Then 125 mg every 48 hours for 1 week
  • Then 125 mg every 72 hours for 1 week 4

Important Clinical Considerations

Advantages of Oral Vancomycin:

• Vancomycin is superior to metronidazole for all cases of CDI 1
• The 125 mg dose is as effective as higher doses (500 mg) with lower cost 3
• Oral vancomycin is not systemically absorbed, minimizing systemic side effects 2

Monitoring Requirements:

• For patients >65 years: Monitor renal function during and after treatment due to increased risk of nephrotoxicity 2
• For patients with inflammatory bowel disorders: Consider monitoring serum vancomycin levels due to potential systemic absorption 2

Key Precautions:

1. Oral use only: Vancomycin capsules are for oral administration only and not for parenteral use 2
2. Discontinue precipitating antibiotics if possible to reduce treatment failure and recurrence risk 1
3. Consider discontinuing proton pump inhibitors if not clinically indicated 1

Special Populations:

• Pediatric patients (<18 years): 40 mg/kg/day divided in 3-4 doses for 7-10 days, not to exceed 2 g daily 2
• Elderly patients (>65 years): Standard dose of 125 mg four times daily, but with closer monitoring of renal function 2

Alternative Treatments to Consider

• Fidaxomicin: 200 mg twice daily for 10 days - particularly beneficial for patients over 65 years or at high risk for recurrence 1, 5
• Fecal microbiota transplantation: Consider after failure of appropriate antibiotic treatments for at least two recurrences 1

Oral vancomycin has become the preferred first-line therapy for CDI regardless of severity, and concerns about increased risk of vancomycin-resistant Enterococci (VRE) with oral vancomycin compared to metronidazole have not been substantiated in research 6.