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

From the Guidelines

Oral vancomycin is typically dosed at 125 mg four times daily for 10 days for initial non-severe episodes of C. difficile infection. For severe infections, the same dose is recommended, while for fulminant C. difficile infection, the dose is increased to 500 mg four times daily, often with intravenous metronidazole 1. The treatment guidelines are based on the most recent recommendations from the Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA) 1.

Key Considerations

• The dose and duration of vancomycin treatment may vary depending on the severity of the infection and the patient's response to treatment 1.
• For first recurrences, the same regimen as the initial episode is recommended, while for multiple recurrences, a tapered and pulsed regimen may be used: 125 mg four times daily for 10-14 days, then 125 mg twice daily for 7 days, then 125 mg once daily for 7 days, followed by 125 mg every 2-3 days for 2-8 weeks 1.
• Vancomycin works by inhibiting bacterial cell wall synthesis and is poorly absorbed from the gastrointestinal tract, allowing it to reach high concentrations in the colon where C. difficile resides.
• The medication should be taken with a full glass of water, and patients should complete the full course even if symptoms improve before completion.
• Common side effects include nausea, abdominal pain, and rarely, rash.

Treatment Options

• Fidaxomicin is an alternative treatment option for C. difficile infection, particularly for patients with severe disease or those who have experienced recurrences 1.
• Metronidazole is also an option for mild to moderate C. difficile infection, but it is not recommended for severe disease due to its lower cure rate compared to vancomycin 1.

Recent Guidelines

The most recent guidelines from the IDSA and SHEA recommend vancomycin as the preferred treatment for initial episodes of C. difficile infection, with fidaxomicin as an alternative option 1. For recurrent C. difficile infection, vancomycin or fidaxomicin may be used, with a tapered and pulsed regimen recommended for multiple recurrences 1.

From the FDA Drug Label

2.1 Adults Vancomycin Hydrochloride Capsules are used in treating C. difficile-associated diarrhea and staphylococcal enterocolitis. C. difficile-associated diarrhea: The recommended dose is 125 mg administered orally 4 times daily for 10 days. The recommended oral vancomycin dosing for C. difficile-associated diarrhea is 125 mg administered orally 4 times daily for 10 days 2.

• Key points:
  • Dose: 125 mg
  • Frequency: 4 times daily
  • Duration: 10 days
• Pediatric dosing is also available: 40 mg/kg in 3 or 4 divided doses for 7 to 10 days, not to exceed 2 g daily 2.

From the Research

Oral Vancomycin Dosing for C. difficile

• The standard dosing for oral vancomycin in the treatment of C. difficile infection is 125 mg four times daily for 10 days, as seen in the study by 3.
• This dosing regimen has been compared to fidaxomicin in several studies, including those by 3, 4, and 5, which found that fidaxomicin was associated with a lower rate of recurrence of C. difficile infection.
• The study by 3 found that the rates of clinical cure with vancomycin were 85.8% in the modified intention-to-treat analysis and 89.8% in the per-protocol analysis.
• The study by 5 found that the CDI recurrence rate was 22.4% with fidaxomicin and 25.4% with vancomycin, and that treatment with fidaxomicin was associated with a 31% reduction in the risk of recurrence.

Comparison to Fidaxomicin

• Fidaxomicin has been shown to be effective in the treatment of C. difficile infection, with several studies comparing its efficacy to that of vancomycin, including those by 3, 4, and 5.
• The study by 4 found that fidaxomicin demonstrated superior clinical outcomes in comparison to vancomycin, with significantly fewer patients experiencing disease recurrence.
• The study by 5 found that fidaxomicin was consistently associated with a lower risk of CDI recurrence than vancomycin, and that this reduction in recurrence risk was seen in subgroup analyses for patients with initial CDI, first recurrent CDI, non-severe and severe CDI, and in both inpatient and outpatient settings.

Safety and Efficacy

• The safety and efficacy of vancomycin and fidaxomicin have been evaluated in several studies, including those by 3, 4, and 6.
• The study by 6 found that fidaxomicin was well tolerated and demonstrated significantly higher rates of global cure in children and adolescents with CDI compared to vancomycin.
• The study by 3 found that the adverse-event profile was similar for vancomycin and fidaxomicin, with no significant differences in the rates of adverse events between the two groups.