Module 9: C. diff TRAT Flashcards
Dr. Covert EMAX VI (Final)
How does C. diff cause harm?
-Toxin A and B
-pro-inflammatory
-toxic to cells of the colon (cytotoxic)
Colonocyte death -> loss of intestinal barrier function -> Colitis
Which strain of C. diff is known to have an increased risk of mortality?
-NAP-1 strain (can be tested for in the hospital)
-hypervirulent
-produces more toxin
Common signs of C. diff
-Abdominal discomfort
-diarrhea
-fever
-Leukocytosis
-toxic megacolon (when untreated)
When should a C. diff infection be considered?
-history of antibiotic use (3 months)
-diarrhea within 72 of hospitalization (but also evaluate if they have other reasons for diarrhea -> other drugs causing diarrhea Senna, docusade, laxatives)
Risk factors of a C. diff infection
-antimicrobial exposure (disruptive GI flora)
-advanced age
-prolonged hospitalization
-chemotherapy/immunosuppression
-GI surgery
-tube feeding
-PPIs > H2RA
Which antibiotics are frequently associated with C. diff?
KNOW
-broad spectrum
-FQ
-Clindamycin
-Penicillins
-Cephalosporins
Which antibiotics are occasionally associated with C. diff?
KNOW
-Macrolides
-Bactrim
rare:
-Aminoglycosides
-Vancomycin (treats C. diff)
-Metronidazole (treas C. diff)
-Tetracyclines
When to test for C. diff
-more than 3 unexplained unformed stools within 24 hrs
-it has to be unexplained (it could be caused by drugs)
-testing patients who are asymptomatic with a history of C. diff is NOT appropriate -> might be positive for weeks or months
How are patients tested for C. diff?
-antigen test: testing for GDH and NAAT -> C. diff in the colon
-stool-toxin test: tells if the C. diff is pathogenic and warrants treatment
-asymptomatic patients with a history of C. diff will probably have a positive antigen test but the stool test will be negative
-no point in testing asymptomatic patients
What is the recommended treatment for C. diff in an initial episode (first time)
IDSA Guidelines 2021
1st line: Fidaxomicin 200 mg PO BID x 10 days
2nd line: Vancomycin 125 mg PO 4x daily - often seen as 1st line because FDX is expensive
3rd line: Metronidazole 500 mg PO daily x 10 days (only if Fidaxomicin/Vanc fails) -> higher failure and recurrence rate
What is the recommended treatment for C. diff in a fulminant phase?
IDSA Guidelines 2021
2 routes necessary
-Vancomycin 500 mg PO daily - 4d (+rectal Vanc if the colon is paralyzed (ileus))
+
-Metronidazole 500 mg IV q8h
How would a patient present in a fulminant phase?
patients with hemodynamic instability: hypotension, shock, ileus (paralyzed colon), megacolon
What is the recommended treatment for C. diff in the 1st recurrence?
IDSA Guidelines 2021
Fidaxmicin 200 mg PO BID x 10 d
or 200 mg BID x 5d and q48h for 21 d
2nd line:
Vanc 125 mg PO 4x daily x 10d or tapered regimen
Adjunctive: Bezlotoxumab 10mg/kg IV once together with FDX/Vanc -> to prevent recurrence
What is the recommended treatment for C. diff in the 2nd recurrence?
IDSA Guidelines 2021
Fidaxmicin 200 mg PO BID x 10 d
or 200 mg BID x 5d and q48h for 21 d
2nd line:
Vanc 125 mg PO 4x daily x 10d, then rifaximin 400 mg PO TID x 20 days OR Vanc in a tapered regimen
-fecal microbiota transplant
Adjunctive: Betoloxumab 10mg/kg IV once with FDX/VNC
MOA of Fidaxomicin
-Macrolide (CAUTIN in macrolide allergy)
-inhibits RNA polymerase sigma unit -> inhibition of protein synthesis
-minimal systemic absorption
200 mg PO BID x 10 days
What is the idea of VNC taper and pulse dosing?
-allowing the dormant spores to become active and killed every 2-3 days
-helps in restoring the normal gut flora
MOA of Betoloxumab
binds and neutralizes the C. diff toxin B
When should Betoloxumab be taken?
Betoloxumab (Zinplava)
recommended by the IDSA guidelines
-for patients with recurrent C. diff episodes within the last 6 months
-dose: 10 mg/kg IV together with FDX/VNC
-CAUTION: higher rates of heart failure in patients with cardiac disease
Which patient population should use Betoloxumab with caution?
higher rates of heart failure in patients with cardiac disease
How does a patient present with antibiotic-associated diarrhea?
-secondary to change in intestinal flora after antibiotic use
-loose stools
-minimal signs of colitis
-no systemic signs of an infection
-no constitutional symptoms like fever, leukocytosis -> seen in C. diff infection
How to treat patients present with antibiotic-associated diarrhea?
-supportive measures (hydration, probiotics, anti-diarrheal agents)
-antibiotic withdrawal (if possible)
Which bacteria commonly cause Traveler’s diarrhea?
Traveler’s diarrhea (foodborne illness)
-Enterotoxigenic E. coli (ETEC)
-Shiga-toxin-producing E. coli (STEC/ Enterohemorrhagic E. coli)
Which E. coli strain should NOT be treated with antibiotics?
Shiga-toxin-producing E. coli (STEC/ Enterohemorrhagic E. coli)
Therapy for traveler’s diarrhea
Signs: watery diarrhea (more than 3 loose stools in 24 hr)
mild-moderate: supportive care
-severe:
*FQ for 1-3 days (for both E. coli or C. jejuni)
*C. jejuni: Azithromycin
*E. coli: Rifaximin
When is a FQ recommended for traveler’s diarrhea?
-when the causing bacteria is not known and the patient can’t be tested
-it targets and Campylobacter jejuni and E. coli
When should anti-diarrheals NOT be used?
in a C. diff infection -> the body tries to get rid of the bacteria
-use it in non-CDI if dehydration is a concern
Loperamide (Imodium)
Diphenoxylate and atropine (Lomotil)
Psyllium
