Clostridioides difficile Infection (CDI)

Is C. diff gram-positive or negative?

Gram-positive

Is C. diff obligately aerobic or anaerobic?

Obligately anaerobic

C diff is a (blank)-producing, (blank)-forming what?

Toxin
Spore
Bacillus

What are the 2 main virulence factors?

Exotoxin A
Exotoxin B

What kind of activity does exotoxin A have?

Enterotoxin activity

What kind of activity does exotoxin B have?

Cytotoxic activity

Exotoxin A and B bind to C. diff receptors on what type of cells?

Intestinal epithelial cells

When C. diff is outside the body, are they active or inactive?

Inactive

Where in the body does C. diff become active?

Intestines

Risk Factors:
Use of what medications?

Antibiotics
Acid-suppressing medications

Risk factors:
What antibiotics can potentially lead to C. diff infections?

Fluoroquinolones
Carbapenems
Clindamycin
Cephalosporins

C. diff - FCCC

Risk Factors:
What acid-suppressing medications can potentially lead to C. diff infections?

Histamine-2 blocker antagonists
PPIs

Risk factors:
What locations are association with C. diff infections?

Hospital
Nursing home

Risk factors:
What surgery is associated with potential C. diff infections?

GI

Risk Factors:
What population is more at risk of C. diff infections?

≥ 65
Immunocompromised

What enzyme is produced in the GI tract during a C. diff infection?

Glutamine dehydrogenase (GHD)*

*non specific

What is specific to active C diff infections?

Exotoxin A
Exotoxin B

What is the time frame of C diff recurrence?

> 2 weeks but < 8 weeks from the index episode

What is the clinical presentation to get C diff diagnostic testing

Unexplained and new onset ≥ 3 unformed stools in 24 hours

Lab/Diagnostic Testing of C diff

NAAT alone
NAAT + toxin
NAAT + GDH + toxin
GDH + toxin

Mushy consistency with ragged edges is what type of unformed stool?

Type 6

Liquid consistency with no solid pieces is what type of unformed stool?

Type 7

CDI Classification:
WBC ≤ 15k cells/mL
AND
Scr < 1.5 mg/dL

Non-severe initial episode

CDI Classification:
WBC ≥ 15k cells/mL
OR
Scr > 1.5 mg/dL

Severe initial episode

CDI Classification:
Hypotension/shock, ileus, or megacolon

Fulminant (severe or sudden onset) CDI

Fidaxomicin:
Class

Macrolide Antibiotic

Fidaxomicin:
MOA

Inhibits RNA polymerase

Fidaxomicin:
Available routes

PO

Fidaxomicin:
ADR

GI bleed
Anemia

All treatments of CDI have what contraindication?

Hypersensitivity

Vancomycin:
Class

Glycopeptide Antibiotic

Vancomycin:
MOA

Inhibits cell wall biosynthesis

Vancomycin:
Available routes

PO, NG, PR

Vancomycin:
ADR

Dysgeusia
Headache
Flatulence

Metronidazole:
Class

Nitroimidazole Antimicrobial

Metronidazole:
MOA

Interacts with DNA

Metronidazole:
Available routes

PO, IV

Metronidazole:
ADR

Metallic taste
Disulfiram reaction
Neurologic symptoms

Which medication is contraindicated in the 1st trimester of pregnancy?

Metronidazole

Which medication requires no alcohol during treatment or within 3 days of discontinuation?

Metronidazole

Which medication has adverse reactions in elderly, ESRD, and people with hepatic impairment?

Metronidazole

What is the preferred medication for non-severe and severe initial episodes of CDI?

Fidaxomicin

Fidaxomicin:
Dose and duration in initial episode CDI treatment

200 mg PO BID x 10 days

What is the first choice of alternative treatment in CDI?

Vancomycin

Vancomycin:
Dose and duration in Initial episode CDI treatment

125 mg PO QID x 10 days

What is the second choice of alternative treatment of CDI?

Metronidazole

Metronidazole:
Dose and duration in initial episode treatment of CDI

500 mg PO TID x 10-14 days

Preferred treatment in recurrent disease of CDI?

Fidaxomicin 200 mg PO BID x 10 days
OR
BID x 5 days f/b QOD x 20 days

Alternative 1A treatment in recurrent disease of CDI?

Vancomycin PO tapered and pulse regimen

Alternative 1B treatment in first recurrence of CDI

Vancomycin 125 mg PO QID x 10 days

What medication should be considered concomitantly with vancomycin treatment in first recurrence of CDI?

Metronidazole

What is the adjunctive therapy in recurrent disease of CDI?

BEZLO 10 mg/kg IV x 1 with SOC (standard of care)

Alternative 1B treatment of subsequent recurrence of CDI?

Vancomycin 125 mg PO QID x 10 days f/b rifaximin 400 mg PO TID x 20 days

What disease of CDI could consider fecal microbiota transplantation?

Subsequent recurrence of CDI

What is the treatment of fulminant CDI?

Vancomycin 500 mg PO or NG QID

What needs to be present in fulminant CDI to consider adding PR instillation of vancomycin?

Ileus

Fulminant CDI suggest concomitant use of what medication with vancomycin treatment?

Metronidazole 500 mg IV QID

What are the medications used to treat CDI?

Fidaxomicin
Vancomycin
Metronidazole

What are the medications to prevent the recurrence of CDI?

Fecal microbiotia
Bezlotoxumab (BELZO)

Fecal Microbiota:
When to give the single dose of 150 mL?

24-72 hours after the last dose of antibiotics

Bezlotoxumab:
When to give the single dose of 10 mg/kg IV

During the treatment of antibiotics over 60 minutes

Fecal microbiota:
ADR

Abdominal distention

Bezlotoxumab:
ADR

pyrexia (fever)

What medication has a warning of heart failure exacerbation in patients with a history of congestive heart failure?

Bezlotoxumab

What is not recommended per guidelines?

Probiotics