What should I do if vancomycin (vancomycin) for Clostridioides difficile (C. difficile) treatment is no longer covered by the pharmacy?

Immediate Action: Address Pharmacy Coverage Issue and Continue Treatment

Contact your pharmacy immediately to clarify the coverage issue, as oral vancomycin 125 mg four times daily for 10 days is the guideline-recommended first-line treatment for C. difficile infection and should be covered for this indication. 1, 2

Critical Problem with Current Regimen

Your patient is receiving vancomycin every 48 hours, which is incorrect dosing for C. difficile treatment:

• Standard dosing is vancomycin 125 mg four times daily (every 6 hours) for 10 days, not every 48 hours 3, 1, 2
• This underdosing may lead to treatment failure and increased risk of complications 1
• The every-48-hour schedule appears to be an error that needs immediate correction regardless of coverage issues 3

Steps to Resolve Coverage Issue

1. Verify the Coverage Problem

• Confirm with pharmacy whether this is a formulary restriction, prior authorization requirement, or insurance denial 3
• Oral vancomycin for C. difficile infection is a standard indication and should be covered 3
• Request pharmacy to submit prior authorization if needed, emphasizing this is for proven CDI 3

2. If Vancomycin Remains Unavailable

Consider these alternatives based on disease severity:

For non-severe disease (WBC ≤15,000 cells/mL AND creatinine <1.5 mg/dL):

• Fidaxomicin 200 mg twice daily for 10 days is equally recommended as first-line therapy 2
• Metronidazole 500 mg three times daily for 10 days only if vancomycin and fidaxomicin are truly inaccessible 1, 2

For severe disease (WBC ≥15,000 cells/mL OR creatinine ≥1.5 mg/dL):

• Vancomycin is mandatory; metronidazole should not be used 3, 2
• If oral route impossible, consider IV metronidazole 500 mg three times daily plus vancomycin enema 3, 1

3. Cost-Effective Vancomycin Options

• Liquid vancomycin formulation is significantly cheaper than capsules and may improve coverage 3
• Request pharmacy to compound vancomycin solution from IV preparation (25 mg/mL oral solution) 3
• Standard 125 mg dose = 5 mL of compounded solution four times daily 3

Critical Warnings About Alternative Approaches

Do not use metronidazole if this is severe disease or if the patient has failed initial therapy, as vancomycin demonstrated 97% cure rate versus 76% for metronidazole in severe disease 2

Avoid repeated or prolonged metronidazole courses due to cumulative and potentially irreversible neurotoxicity risk 2

Do not continue inadequate dosing (every 48 hours) while resolving coverage—this increases mortality risk 3, 1

Monitoring During Coverage Resolution

• Assess clinical response within 72 hours of correct dosing 1, 2
• Rising WBC ≥25,000 or lactate ≥5 mmol/L indicates potential surgical need 1
• Treatment failure (no improvement by day 3-5) requires escalation, not continuation of inadequate therapy 2