What is the management of pseudomembranous enterocolitis?

Management of Pseudomembranous Enterocolitis

Immediately discontinue the inciting antibiotic and initiate oral vancomycin 125 mg four times daily for 10 days as first-line therapy, particularly for severe disease. 1, 2, 3

Immediate Initial Steps

• Stop the offending antibiotic immediately upon suspicion of C. difficile infection, as continued use significantly increases recurrence risk 1, 2
• If ongoing antibiotic therapy is essential for another concurrent infection, switch to agents less commonly associated with CDI: parenteral aminoglycosides, sulfonamides, macrolides, vancomycin, or tetracycline/tigecycline 1
• Consider empirical therapy while awaiting test results only if there is strong clinical suspicion for severe CDI, defined by fever, leukocytosis (WBC ≥15,000/mm³), hypoalbuminemia, or ≥10 unformed bowel movements per day 1

First-Line Antibiotic Treatment

For severe disease or when severity is uncertain:

• Oral vancomycin 125 mg four times daily for 10 days is the preferred first-line treatment, with clinical success rates of approximately 80% 1, 3
• This regimen demonstrated superior efficacy compared to metronidazole in severe CDI 1
• The FDA-approved dosing for adults is 125 mg orally four times daily for 10 days specifically for C. difficile-associated diarrhea 3

For mild-to-moderate disease:

• Oral metronidazole remains effective with 97% cure rates in non-severe cases and offers advantages of lower cost and reduced selection pressure for vancomycin-resistant enterococci 1, 2
• However, metronidazole is inferior to vancomycin in severe disease 2

For pediatric patients (<18 years):

• The usual daily dosage is 40 mg/kg in 3 or 4 divided doses for 7 to 10 days, not to exceed 2 g total daily 3

Management of Severe-Complicated Disease

• Urgent surgical consultation is mandatory for patients showing signs of systemic toxicity, peritonitis, or clinical worsening despite medical therapy 1, 2
• Resectional procedures (colectomy) carry better prognosis than diversion procedures (colostomy) when surgery becomes necessary 4
• Toxic megacolon and acute peritonitis secondary to colonic perforation are the most serious complications requiring surgical intervention 5

Recurrent Disease Management

For first recurrence:

• Repeat the same antibiotic regimen that was initially successful 2

For multiple recurrences (≥2 episodes):

• Consider extended/pulsed vancomycin or fidaxomicin, which significantly reduce recurrence rates compared to standard vancomycin 1, 2
• Bezlotoxumab (monoclonal antibody) can be added to reduce recurrence risk 1, 2

For refractory cases:

• Fecal microbiota transplantation (FMT) should be considered after failure of three courses of antibiotics, with 92% clinical resolution rates across studies 2
• For FMT failure in pseudomembranous colitis specifically, repeat FMT every 3 days until resolution of pseudomembranes 2

Diagnostic Considerations

• Flexible sigmoidoscopy may be helpful when stool assays are negative but clinical suspicion remains high, as the typical endoscopic appearance is often diagnostic 6, 1
• Colonoscopy is contraindicated in fulminant colitis due to very high perforation risk 6, 1
• CT imaging assists with diagnosis and severity assessment in severe-complicated disease, though sensitivity is only 52% 1
• In neutropenic patients, pseudomembrane formation may be absent or altered, requiring endoscopic biopsy for diagnosis 6, 1

Monitoring and Special Populations

Elderly patients (>65 years):

• Monitor renal function during and following treatment, as nephrotoxicity risk is increased in this population even with normal baseline renal function 3
• Clinically significant serum concentrations can occur with oral vancomycin in patients with inflammatory intestinal mucosa, particularly those with renal insufficiency 3

Patients with inflammatory bowel disorders:

• Significant systemic absorption of oral vancomycin may occur, warranting serum concentration monitoring in some instances 3

Critical Pitfalls to Avoid

• Do not perform "test of cure" after treatment, as 56% of successfully treated patients asymptomatically shed C. difficile spores for up to 6 weeks 2
• Do not repeat testing after initiating treatment unless there are clear clinical changes, as test positivity does not correlate with treatment failure 1, 2
• Do not treat asymptomatic carriage with C. difficile 2
• Distinguish recurrent CDI from post-infectious irritable bowel syndrome, which can cause symptoms in up to 35% of patients during the first 2 weeks and 4.3% beyond 3 months 2
• Recurrence rates of 20-39% are expected even with appropriate therapy; this represents true recurrence rather than treatment failure 7, 5