Therapeutics - GI infections part 1 Flashcards
is Clostridium/colstridios difficile:
spore forming?
toxin-producing?
gram positive or negative?
aerobic or anaerobic?
shape?
spore forming
toxin-producing
gram (+)
anaerobic
bacillus
true or false
clostridium/clostridios difficile can cause a wide spectrum of syndromes
TRUE
can be asymptomatic, colitis, diorrhea, perforation, even death
_____ is the major identifiable cause of antibiotic-associated bacteria
c diff infection
responsible for 15-25% of all cases
CDI has been having increased incidence in what setting?
the community setting
also, there are high rates of recurrent infection
true or false
there are low rates of recurrent c diff infection
FALSE
high rates of recurrent infeciton
how is CDI transmitted?
fecal-oral route by ingesting spores
ie - from hospital rooms, hands, clothes, stetchoscope of HC workers
explain appropriate hand hygiene when in contact with patients who have c diff infection
what will NOT work
alcohol-based hand sanitizers will NOT remove the c diff spores.
SOAP AND WATER is preferred technique
2 modifiable risk factors for getting a c diff infection
antibiotic use
acid-suppressing agents
which acid-suppressing agents have a greater risk of c diff infection?
PPIS (omeprazole) have greater risk than H2RAs (famotidine)
what are some nonmodifiable risk factors for getting a c diff infection
older than 65
immunosuppressed
recent hospital admission (past 60 days)
end stage renal disease
mechanical ventilation
envoronmental factors that can be risk factor for c diff infection
improper infection control
true or false
pregnancy is a risk factor for commmunity onset c diff infection
TRUE
name 6 high risk antibiotics for getting a c diff infection
beta lactams: penicillins (w or w/o b lactamase inhibitor), carbapenems, cephalosporins
clindamycin
fluoroquinolones
ANY combination therapy
name 6 “lower risk” antibiotics for getting c diff infection
tetracyclines
glycopeptides
oxazolidinones
metronidazole
nitrofurantoin
bactrim
true or false
all antibiotics can cause c diff infection
TRUE
some are just higher risk than others
explain when a c diff infection can be diagnosed
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
a patient is on a laxataive and has had 5 unformed stools in the last 24 hours
should they be tested for c diff?
NO
this is EXPLAINED - they’re on a laxative
only test if the loose stools are UNEXPLAINED
a patient is known to have c diff from an antibiotic that they are currently on.
what should be done
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
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?
we should start empiric therapy even while awaiting the diagnosis
the treatment regimen for c diff infection depends on a number of factors such as—
is the the initial episode or recurrent?? is it fulminant? (sudden and SEVERE onset - hypotension, shock, ileus, mega colon)
2 parameters in which a c diff infection is NON SEVERE
WBC less than 15,000 AND SCr less than 1.5mg/dL
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)?
preferred - fidaxomicin 200mg PO Q12 X 10 days
alternative - vanco 125mg PO Q6 X 10 DAYS
IF NON SEVERE - metronidazole 500mg PO Q8
explain the regimen for a FIRST RECURRENCE c diff infection
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)
preferred therapy for first recurrent c diff infection is fidaxomicin
why might the alternative - vancomycin - be used??
fidaxomicin is preferred bc it’s better at preventing recurrences. however, it’s expensive, so cost may be a reason to use vanco instead
what is the rationale for using pulse therapy in c diff infection
(for fidaxomicin or vanco)
weans them off the antibiotic - gives body the chance to restore the normal intestinal flora
bezlotoxumab + fidaxomicin should be used with caution in which population?
congestive heart failure patients. limited data on using them together
pt has 1st recurrence c diff infection. initial infection was treated with metronidazole
knowing this, what should you use to treat this recurrence?
vanco 125mg PO q6 x 10 days
(or pulsed PO)
recommended regimens for 2nd or more recurrences of c diff infection
-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
before offering fecal microbiota transplant to patients, what is the requirement
this must be their 2nd (or more) recurrences) and they must have tried and failed c diff therapy 3 times
recommended treatment for fulminant c diff infection
what is fulminant c diff infection?
hypotension or shock, ileus, mega colon
vanco 500mg PO Q6
if ileus: ADD rectal vanco and IV metronidazole
brand name fidaxomicin
dificid
MOA of fidaxomicin
inhibits RNA polymerase - resulting in inhibition of protein synthesis and ultimate death of c. difficile
fidaxomicin:
-adverse reactions
-warnings/precautions
adverse reactions - nausea, GI bleed, abdominal pain, vomiting
warnings- use with caution in patients with MACROLIDE ALLERGY !!! cross sensitivity
brand name bezlotoxumab
zinplava
true or false
bezlotoxumab is NOT indicated for the treatment of c diff infection
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
dose of bezlotoxumab
10mg/kg IV as single dose
MOA bezlotoxumab
it is an IgG1 MAB which binds to the c diff toxin B in hopes to neutralize it and prevent recurrence
bezoltoxumab:
-adverse reactions
-warnings/precautions
adverse reactions - heart failure exacerbation, headache, GI
warnings - high mortality when used in patients with history of HEART FAILURE
explain what FMT (fecal microbiota transplant) is
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
3 routes of administration of FMT
oral
nasogastric or gastric tube
rectum
2 FDA approved products that are FMT
vowst
rebyota
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?
age
recent hospitalization
mechanical ventilation
true or false
the use of omeprazole is a MODIFIABLE risk factor for developing c diff infection
TRUE
H2RA antagonists preferred like famotidine
INITIAL INFECTION
labs: WBC 17,000 and serum creatinine 2.7mg/dL
anaphylactic reaction to azithromycin
what regimen should be started
vanco 125mg PO Q6H
DO NOT USE FIDAXOMICIN!!!!! cross sensitivity with macrolides like azithromycin
LABS INDICATE SEVERE INFECTION – do not use metronidazole
