Therapeutics - GI infections part 1

Question 1

is Clostridium/colstridios difficile:
spore forming?
toxin-producing?
gram positive or negative?
aerobic or anaerobic?
shape?

Answer 1

spore forming
toxin-producing
gram (+)
anaerobic
bacillus

Question 2

true or false

clostridium/clostridios difficile can cause a wide spectrum of syndromes

Answer 2

TRUE

can be asymptomatic, colitis, diorrhea, perforation, even death

Question 3

_____ is the major identifiable cause of antibiotic-associated bacteria

Answer 3

c diff infection

responsible for 15-25% of all cases

Question 4

CDI has been having increased incidence in what setting?

Answer 4

the community setting

also, there are high rates of recurrent infection

Question 5

true or false

there are low rates of recurrent c diff infection

Answer 5

FALSE

high rates of recurrent infeciton

Question 6

how is CDI transmitted?

Answer 6

fecal-oral route by ingesting spores

ie - from hospital rooms, hands, clothes, stetchoscope of HC workers

Question 7

explain appropriate hand hygiene when in contact with patients who have c diff infection

what will NOT work

Answer 7

alcohol-based hand sanitizers will NOT remove the c diff spores.

SOAP AND WATER is preferred technique

Question 8

2 modifiable risk factors for getting a c diff infection

Answer 8

antibiotic use

acid-suppressing agents

Question 9

which acid-suppressing agents have a greater risk of c diff infection?

Answer 9

PPIS (omeprazole) have greater risk than H2RAs (famotidine)

Question 10

what are some nonmodifiable risk factors for getting a c diff infection

Answer 10

older than 65

immunosuppressed

recent hospital admission (past 60 days)

end stage renal disease

mechanical ventilation

Question 11

envoronmental factors that can be risk factor for c diff infection

Answer 11

improper infection control

Question 12

true or false

pregnancy is a risk factor for commmunity onset c diff infection

Answer 12

TRUE

Question 13

name 6 high risk antibiotics for getting a c diff infection

Answer 13

beta lactams: penicillins (w or w/o b lactamase inhibitor), carbapenems, cephalosporins

clindamycin
fluoroquinolones

ANY combination therapy

Question 14

name 6 “lower risk” antibiotics for getting c diff infection

Answer 14

tetracyclines
glycopeptides
oxazolidinones
metronidazole
nitrofurantoin
bactrim

Question 15

true or false

all antibiotics can cause c diff infection

Answer 15

TRUE

some are just higher risk than others

Question 16

explain when a c diff infection can be diagnosed

Answer 16

UNEXPLAINED and new onset of 3 or more unformed stools in 24 hours SHOULD BE TESTED FOR C DIFF INFECTION

there are several tests, but guidelines recommend stool toxin test

C diff infection is diagnosed when the lab test is postive AND patient has 3 or more UNEXPLAINED unformed stools in 24 hours

Question 17

a patient is on a laxataive and has had 5 unformed stools in the last 24 hours

should they be tested for c diff?

Answer 17

NO

this is EXPLAINED - they’re on a laxative

only test if the loose stools are UNEXPLAINED

Question 18

a patient is known to have c diff from an antibiotic that they are currently on.

what should be done

Answer 18

IF POSSIBLE, discontinue treatment with that antibiotic or switch to lower risk one

however, this isn’t possible most of the time is pt is in a life-threatening emergency like septic shock

Question 19

we are awaiting the lab results in a patient who has suspected c diff

should we start any empiric antibiotics or wait until the infection is definite?

Answer 19

we should start empiric therapy even while awaiting the diagnosis

Question 20

the treatment regimen for c diff infection depends on a number of factors such as—

Answer 20

is the the initial episode or recurrent?? is it fulminant? (sudden and SEVERE onset - hypotension, shock, ileus, mega colon)

Question 21

2 parameters in which a c diff infection is NON SEVERE

Answer 21

WBC less than 15,000 AND SCr less than 1.5mg/dL

Question 22

preferred regimen for initial c diff infection? alternative regimen?

what if this initial infection is NON SEVERE (WBC less than 15,000 and serum creatinine less than 1.5)?

Answer 22

preferred - fidaxomicin 200mg PO Q12 X 10 days

alternative - vanco 125mg PO Q6 X 10 DAYS

IF NON SEVERE - metronidazole 500mg PO Q8

Question 23

explain the regimen for a FIRST RECURRENCE c diff infection

Answer 23

preferred regimen:
fidaxomicin 200mg PO q12 for 10 days OR pulsing therapy (taper) —- fidaxomicin 200mg PO Q12 for 5 days, then daily every other day for x days

alternatives - vanco PO (pulsed) OR vanco 125mg PO Q6 10 days

ADJUNCTIVE — given with bezlotoxumab 10mg/kg iv once (to prevent future recurrences)

Question 24

preferred therapy for first recurrent c diff infection is fidaxomicin

why might the alternative - vancomycin - be used??

Answer 24

fidaxomicin is preferred bc it’s better at preventing recurrences. however, it’s expensive, so cost may be a reason to use vanco instead

Question 25

what is the rationale for using pulse therapy in c diff infection
(for fidaxomicin or vanco)

Answer 25

weans them off the antibiotic - gives body the chance to restore the normal intestinal flora

Question 26

bezlotoxumab + fidaxomicin should be used with caution in which population?

Answer 26

congestive heart failure patients. limited data on using them together

Question 27

pt has 1st recurrence c diff infection. initial infection was treated with metronidazole

knowing this, what should you use to treat this recurrence?

Answer 27

vanco 125mg PO q6 x 10 days
(or pulsed PO)

Question 28

recommended regimens for 2nd or more recurrences of c diff infection

Answer 28

-fidaxomicin 200mg PO q12 for 10 days OR q12 for 5 days and then daily every other day for 20 DAYS

-vanco PO taper OR Vanco 125mg PO q12 for 10 days, then RIFAXIMIN 400mg TID for 20 days

-fecal microbiota transplant

-ADJUNCTIVE = BEZLOTOXUMAB 10MG/KG IV X1

Question 29

before offering fecal microbiota transplant to patients, what is the requirement

Answer 29

this must be their 2nd (or more) recurrences) and they must have tried and failed c diff therapy 3 times

Question 30

recommended treatment for fulminant c diff infection

what is fulminant c diff infection?

Answer 30

hypotension or shock, ileus, mega colon

vanco 500mg PO Q6

if ileus: ADD rectal vanco and IV metronidazole

Question 31

brand name fidaxomicin

Answer 31

dificid

Question 32

MOA of fidaxomicin

Answer 32

inhibits RNA polymerase - resulting in inhibition of protein synthesis and ultimate death of c. difficile

Question 33

fidaxomicin:

-adverse reactions
-warnings/precautions

Answer 33

adverse reactions - nausea, GI bleed, abdominal pain, vomiting

warnings- use with caution in patients with MACROLIDE ALLERGY !!! cross sensitivity

Question 34

brand name bezlotoxumab

Answer 34

zinplava

Question 35

true or false

bezlotoxumab is NOT indicated for the treatment of c diff infection

Answer 35

TRUE

it’s used in patients 18 and older who are ALREADY RECEIVING C DIFF TREATMENT and are a thigh risk of recurrence to REDUCE RECURRENCE

IT WILL NOT CURE THE C DIFF INFECTION

Question 36

dose of bezlotoxumab

Answer 36

10mg/kg IV as single dose

Question 37

MOA bezlotoxumab

Answer 37

it is an IgG1 MAB which binds to the c diff toxin B in hopes to neutralize it and prevent recurrence

Question 38

bezoltoxumab:

-adverse reactions
-warnings/precautions

Answer 38

adverse reactions - heart failure exacerbation, headache, GI

warnings - high mortality when used in patients with history of HEART FAILURE

Question 39

explain what FMT (fecal microbiota transplant) is

Answer 39

reintroduces normal intestinal flora into the GI tract. this is done by healthy human stool being instilled into the GI tract of the colon where the normal flora is missing

Question 40

3 routes of administration of FMT

Answer 40

oral
nasogastric or gastric tube
rectum

Question 41

2 FDA approved products that are FMT

Answer 41

vowst
rebyota

Question 42

pt is 96 year old male recently discharged after being treated for pneumonia with cefepime.

during hospital admission, he required mechanical ventilation and was started on omeprazole for stress ulcer prophylaxis.

he is now presenting with suspected CDI

what are his NON MODIFIABLE risk factors for developing CDI?

Answer 42

age
recent hospitalization
mechanical ventilation

Question 43

true or false

the use of omeprazole is a MODIFIABLE risk factor for developing c diff infection

Answer 43

TRUE

H2RA antagonists preferred like famotidine

Question 44

INITIAL INFECTION
labs: WBC 17,000 and serum creatinine 2.7mg/dL

anaphylactic reaction to azithromycin

what regimen should be started

Answer 44

vanco 125mg PO Q6H

DO NOT USE FIDAXOMICIN!!!!! cross sensitivity with macrolides like azithromycin

LABS INDICATE SEVERE INFECTION – do not use metronidazole