C. Diff Flashcards
What is Clostridioides difficile associated diarrhea? (3 criteria, well, more like 2 + 1)
- Diarrhea - ≥ 3 unformed stools per 24h for ≥ 2 days with no other recognized cause
- Diarrhea will not occur in the presence of ileus - AND detection of toxin A or B in the stool or toxin-producing C. difficile in the stool
- OR visualization of pseudomembranes in the colon via colonscopy
When should C. diff associated diarrhea be suspected?
In patients with recent antibiotic use - within the previous 3 months
How does C. diff manifest clinically? (5)
- Diarrhea - almost never grossly bloody
- Distinct odor - Fever - 28% of cases
- Abdominal pain - 22%
- Leukocytosis - 50%
- May present with mild diarrhea to life-threatening toxic megacolon
What is the pathogenesis of C. diff? (3)
Step 1 - exposure to antimicrobial agents establishes susceptibility to CDI through disruption of normal colonic microbiota
Step 2 - exposure to toxigenic C. diff
Step 3 - virulent strain or high risk antibiotic or inadequate host immune response
C. diff is acquired ___________ - most often in ________ or _______ ______
exogenously; hospital; nursing homes
What is the morphology of C. diff? (4)
- Gram positive
- Spore forming
- Anaerobic bacillus
- Causes toxin mediated disease - two toxins - A and B (diagnosis is confirmed by the presence of these toxins)
All antibiotics have been associated with CDI, including those used to treat it. Which ones have the highest risk though? (5)
- Clindamycin
- Fluoroquinolones
- Cephalosporins (esp. 3rd and 4th generation)
- Ampicillin
- Carbapenems
All antibiotics have been associated with CDI, including those used to treat it. Which ones have the lowest risk though? (5)
- Penicillin
- Macrolides
- Tetracycline
- TMP/SMX
- Aminoglycosides
Risk of CDI continues until _ months past antibiotic therapy
3
What are the risk factors for CDI? (7)
- Older age
- Greater severity of underlying disease
- Gastrointestinal surgery
- Use of rectal electronic thermometers
- Enteral tube feeding
- Antacid therapy - PPIs > H2RAs
- Hospitalization - linked to # of days
What are 3 important features to note about CDI recurrences?
- Recurrences are common - 15-30% for first recurrence
- Recurrences may be relapse (same strain) or new infection (new strain)
- Different strains produce greater amounts of toxin
How is CDI managed? (4)
- Stop the offending antibiotic - if possible
- Fluid and electrolyte replacement therapy
- Avoid drugs which inhibit peristalsis such as diphenoxylate/atropine and loperamide
- Categorize as mild to moderate vs. severe AND uncomplicated vs. complicated
Severe CDI is defined as?
What does severe-complicated also include?
Severe - Leukocytes ≥ 15,000 cell/ul and/or SCr ≥ 1.5x baseline
Severe-complicated - hypotension, shock, ileus or megacolon
What is the first-line medication for mild to moderate initial episode of CDI? What is the dosing and for how long?
Vancomycin 125mg PO QID for 10-14 days
What are the 2 alternative medications for mild to moderate initial episode of CDI? What is the dosing and for how long?
- Fidamoxicin 200mg PO BID for 10 days
- Metronidazole 500mg PO TID for 10-14 days can be used in patients with mild diarrhea when the costs of vancomycin or fidaxomicin may be prohibitive for their use
What are the 2 drug treatment options for severe-uncomplicated initial episode of CDI? What is the dosing and for how long?
- Vancomycin 125mg PO QID for 10-14 days or
- Fidamoxicin 200mg PO BID for 10 days
What is the first-line drug treatment for severe-complicated initial episode of CDI? What is the dosing and for how long? (2)
- Vancomycin 125-500mg PO QID for 10-14 days or via NG tube in conjunction with metronidazole 500mg IV Q8H
- Vancomycin retention enema sometimes added if ileus
What is the alternative drug treatment for severe-complicated initial episode of CDI? What is the dosing and for how long?
Fidamoxicin 200mg PO BID for 10 days with IV metronidazole if severe allergy to PO vancomycin
What is the drug treatment option for a first recurrence of CDI?
Same as initial episode (vancomycin or fidaxomicin - same doses)
What is the main drug treatment option for second or subsequent recurrences of CDI?
Vancomycin as a prolonged taper and/or pulsed regimen
- E.g., 125mg QID x 14 days; 125mg TID x 7 days; 125mg BID x 7 days; 125mg once daily x 7 days; 125mg every 2 or 3 days for 2-8 weeks
What are 3 alternative treatment options for second or subsequent recurrences of CDI?
- Fecal microbiota transplantation (FMT)
- Monoclonal antibody that binds to toxin
- Toxin A = actoxumab
- Toxin B = bezlotoxumab - Surgery
True or False? In terms of diagnosis, treatment, and complications - CDI in pediatrics is the same as adults
True
What are the 2 drug treatment options for mild to moderate initial episode of CDI in pediatrics? Should know the dosing and for how long.
(Same applies to first recurrence, mild to moderate)
One of:
1. Metronidazole 30mg/kg/day PO QID for 10 days (max 500mg/dose)
2. Vancomycin 40mg/kg/day PO QID for 10 days (max 125mg/dose)
What is the drug treatment option for severe-uncomplicated initial episode of CDI in pediatrics? Should know the dosing and for how long.
(Same applies to first recurrence, severe, uncomplicated)
Vancomycin 40mg/kg/day PO QID for 10 days (max 125mg/dose)
