Clostridioides difficile

Microbiology

• Spore-forming, anaerobic, Gram-positive bacillus

Severity

Severity	Definition
Mild	WBC ≤15 AND creatinine ≤1.5 x baseline
Severe, uncomplicated	WBC >15 OR creatinine >1.5 x baseline OR hypoalbuminemia
Severe, complicated	Hypotension OR shock OR ileus OR megacolon

Management

Severity	First-line	Alternatives
Initial episode
Mild to moderate	Vancomycin 125 mg po QID for 10-14 days	Fidaxomicin 200 mg po BID for 10 days Metronidazole 500 mg po TID for 10-14 days
Severe, uncomplicated	Vancomycin 125 mg po QID for 10-14 days Fidaxomicin 200 mg po BID for 10 days
Severe, complicated	Vancomycin 125-500 mg po QID for 10-14 days plus metronidazole 500 mg IV q8h	Fidaxomicin 200 mg po BID for 10 days plus metronidazole 500 mg IV q8h Consider rectal vancomycin if ileus
Recurrent episode
First recurrence, mild to moderate	Vancomycin 125 mg po QID for 14 days	Fidaxomicin 200 mg po BID for 10 days
First recurrence, severe, uncomplicated	Vancomycin 125 mg po QID for 14 days Fidaxomicin 200 mg po BID for 10 days
Second or subsequent recurrence	Vancomycin as prolonged tapered or pulsed regimen	Consider fecal microbiota tranplantation after vancomycin

• For rectal vancomycin, add 500 mg to 100 mL normal saline and give as retention enema every 6 hours
• A sample vancomycin taper: 125 mg po QID for 14 days, then 125 mg po TID for 7 days, then 125 mg po BID for 7 days, then 125 mg po daily for 7 days, then 125 mg po q2-3d for 2 to 8 weeks

Further Reading

• AMMI treatment practice guidelines for Clostridium difficile infection 2018
• Clostridioides difficile: diagnosis and treatments. BMJ. 2019;366:l4609. doi: 10.1136/bmj.l46091