Lecture 8 - GI Infections 2

Question 1

Toxin A vs B

Answer 1

Toxin A = make sick
Toxin B = virulence

Question 2

C.Diff Risk factors

Answer 2

Meds = Abx, acid suppressing, chemo
Advanced age
Hospialization
Severe illness = immunocompromised, stem cell transplant
Enteral feeding
Obesity
GI surgery

Question 3

Risk factors for recurrent C.diff

Answer 3

Age > 75
> 10 unformed stools/24hrs
SCr > 1.2mg/dL

Question 4

C.diff has resistance to…

Answer 4

Clindamycin and fluoroquinolone, cause increases virulence

Question 5

C.diff clinical presentation

Answer 5

Asymptomatic -> full blown diarrhea
Typical onset w/I 2-3 days of colonization
Foul-smelling, greenish, watery stools
Ab discomfort, cramping
Fever (103/104)
Nausea, anorexia
Inc WBC, SCr, Lactate

Question 6

C.diff complications

Answer 6

Dehydration, electrolyte disturbance
Post-infectious IBS
Fulminant colitis = bunch of issues
Death

Question 7

What agents to avoid C.diff?

Answer 7

Antiperistaltic agents

Question 8

C.diff diagnosis

Answer 8

> 3 unformed stools in < 24hrs or radiographic evidence

• Liquid stool, positive test for toxigenic C.diff, imaging

Difference w/ community acquired = symptoms present n no prior inpatient stay 12weks before onset

Question 9

C.diff diagnostic testing

Answer 9

1. Clinical evidence of C.diff
2. Send stool for GDH (antigen) and Toxin (A/B EIA)

Both positive = C.diff +
Both negative = C.diff -
If antigen + / toxin - then do NAAT PCR

if toxin positive = C.diff positive

Question 10

C.diff prevention

Answer 10

surveillance/early detection
Hand hygiene contact precautions
environmental control

Question 11

C.diff approach to therapy

Answer 11

D/c - acid suppression, constipation, diarrheal

Classify

Select txm

Question 12

Non-severe C.diff

Answer 12

WBC < 15 and SCr < 1.5

Question 13

Severe C.diff

Answer 13

WBC > 15 or SCr > 1.5

Question 14

Fulminant is….

Answer 14

associated with hypotension or shock or ileum or megacolon

essentially icu

Question 15

How to treat initial Fulminant

Answer 15

Vancomycin 500mg PO/via GT q6h

if ileum, + PR Vanco +/- metronidazole IV

Question 16

Initial C.diff treatment if non-severe or severe?

Answer 16

Preferred: Fidaxomicin 200mg PO BID X 10 days
Alternative: Vancomycin 125mg PO q6H X 10 days

Question 17

Can you use IV vanco for C.diff??

Answer 17

nah, use PO

Question 18

What to use for non-severe C.diff if no fidaxomicin/vanco available?

Answer 18

Metronidazole 500mg PO TID X 10-14 days

cant use for severe

Question 19

1st recurrence (2nd episode) C.diff treatment

Answer 19

1. Fidaxomicin 200mg BID X 10days
2. prolonged tapered and pulsed vanco regiment
3. vanco 125mg Q6h X 10 days; opinion if metronidazole used for 1st episode

adjunctive: bezlotoxumab 10mg/kg IV x 1 w/ antibiotics. caution in pts with congestive HF

Question 20

2nd recurrence (3+ episode)

Answer 20

1. fidaxomicin 200mg PO BID X 10 days or fidaxomicin 200mg X5 days then every other 20days
2. vanco tapered and pulsed
3. vanco 125mg q6h x 10 days followed by rifaximin 400mg q8h x 20 days
4. fecal microbiota transplantation

adjunctive: bezlotoxumab 10mg/kg IV x 1 w/ antibitoics. caution in pts w/ congestive HF

Question 21

Prophylaxis for recurrent C.diff

Answer 21

insufficient evidence for/against

IF using: Vanco 125mg BID during abx txm then atleast 1 day following d/c of abx

Metronidazole/fidaxomicin are not recommended

Question 22

vanco MOA

Answer 22

inhibit cell wall synthesis, bacteriostatic against C.diff

Question 23

Fidaxomicin MOA

Answer 23

Macrolide, bind 50S ribosomal subunit leading to protein synthesis inhibition
Bactericidal

Question 24

Metronidazole MOA

Answer 24

DNA disruption, inhibits nucleic acid synthesis thus damaging bacterial cells

** peripheral neuropathy inc with inc dose over time ***

Question 25

who should not get probiotics

Answer 25

no immunocompromised critically ill impaired intestinal barrier

Question 26

Fecal microbiota transplantation

Answer 26

move poop from one person to another super effective

Question 27

H.pylori risk factors

Answer 27

male gender diet food prep methods stress

Question 28

Med interactions for Endoscopic testing

Answer 28

Hold PPI for 2 weeks before Abx can alter sensitivity, wait 4 weeks

Question 29

OG H.pylori recommended treatment

Answer 29

Clarithromycin Triple therapy for 14 days ** if resistance < 15% and no macrolide exposure for any reason ** PPI/H2RA + Clarith 500 BID + Amoox 1g BID/ Metronidazole 500 TID if allergy (Prevpac)

Question 30

Bismuth-based Quadruple therapy

Answer 30

10-14 days, often 14 ** option if macrolide exposure or penicillin allergy ** PPI/H2RA + Bismuth subsal QID + Metronidazole 250 QID or 500 TID/QID + tetracycline 500mg QID Prilosec + Pylera

Question 31

Concomitant therapy

Answer 31

10-14 days ** option if clarithromycin resistance > 15% or repeated exposure ** PPI BID + Amox 1g BID + Metronidazole 500mg BID + Clarithromycin 500mg BID

Question 32

Sequential therapy

Answer 32

PPI + Amox/ Levo if allergy + metronidazole (after amoxicillin) + clarithromycin (after amoxicillin)

Question 33

Hybrid Therapy

Answer 33

PPI + amoxicillin + metronidazole (days 8-14) + clarithromycin (days 8-14)

Question 34

levofloxacin Triple Therapy

Answer 34

PPI + amoxicillin + levofloxacin

Question 35

Levofloxacin sequential therapy

Answer 35

PPI + amoxicillin + Levo (days 7+) + metronidazole (days 7+)

Question 36

If PCN allergy + no macrolide exposure, what are options?

Answer 36

Bismuth-based quadruple Calrithromycin triple w/ metronidazole

Question 37

If PCN allergy + Macrolide exposure, what are options?

Answer 37

Bismuth based quadruple

Question 38

No PCN allergy + Macrolide exposure, what are options?

Answer 38

Bismuth-based quadruple Levo triple Levo sequential Concomitant, hybrid, LOAD

Question 39

No PCN allergy + No macrolide exposure, what are options?

Answer 39

All of them

Question 40

H.pylori Salvage treatment

Answer 40

confirm eradication in high risk groups can use UBT, SAT or endoscopy test, have to wait 4weeks after abx to retest refer to specialist if still positive to H.pylori

Question 41

Salvage Treatment Regimens

Answer 41

Bismuth-based Quadruple therapy*** Levoflox triple therapy*** Concomitant therapy for 10-14 days Rifabutin Triple therapy for 10 days High dose Dual therapy for 14 days

Question 42

Rifabutin Triple Therapy

Answer 42

PPI + amoxicillin + rifabutin

Question 43

High dose dual therapy

Answer 43

PPI + Amox

Question 44

Salvage therapy if started clarithromycin-triple

Answer 44

bismuth-based quad start

Question 45

Salvage therapy if started bismuth-quad

Answer 45

levo triple start

Question 46

Talicia

Answer 46

Rifabutin Based Therapy Admin: 4 tabs q8hrs w/ food for 14 days avoid use in creatine clearance < 30 combo of omeprazole, amoxicillin, rifabutin