041415 diarrhea

Question 1

when would you order labs?

Answer 1

when pt is toxic appearing

Question 2

would you get C diff tests?

Answer 2

no (if it’s NOT bloody diarrhea)

Question 3

number one cause of acute diarrhea

Answer 3

infectious

Question 4

differential diagnosis for acute, non-bloody diarrhea

Answer 4

see slide 5

Question 5

preferred drugs for campylobacter jejuni

Answer 5

quinolones (ciprofloxacin)–inhibits DNA gyrase/topoisomerase

azithromycin, erythromycin–bind 50S ribosomal subunit and block mRNA translocation

Question 6

compare erythromycin and azithromycin

Answer 6

azithromycin has: lower incidence of GI effects, lower incidence of cardiac effects, few drug interactions, less frequent dosing

erythromycin: pro-kinetic agent, risk for arrhthmias and cardiac arrest, CYP3A inhibitor, more freq dosing

Question 7

which would you use for campylobacter jejuni: ciprofloxacin or azithromycin?

Answer 7

campylobacter is less resistant to azithromycin in the US and other countries

Question 8

similarites btwn shigella and salmonella

Answer 8

enterobacteriaceae family
facultative anaerobes
gram neg rods

beta lactamase has become common in this family

Question 9

what tx is used for shigella and salmonella (non-typhi)

Answer 9

ciprofloxacin
ceftriaxone
azithromycin

(the approved drugs are ampicillin for both, TMP/SMX for shigella, and cipro for both-HOWEVER, there’s greater resistance to ampicillin and TMP/SMX)

Question 10

after antibiotic use, if pt gets fever, bloody diarrhea, what should you do?

Answer 10

test stool for C diff

Question 11

FDA approved tx for C diff

Answer 11

vancomycin

fidaxomicin

Question 12

tx that can be used for C diff

Answer 12

• vancomycin (only oral)
• fidaxomicin (just covers C diff, so adv is that it doesn’t disrupt normal flora as much) -also only oral
• metronidazole (oral or IV)

Question 13

fidaxomicin MOA

Answer 13

inhibits RNA polymerase

Question 14

recurrence of C diff is significantly assoc w

Answer 14

use of antibacterials that disrupt normal flora

Question 15

side effects of oral vanco

Answer 15

nausea, abd pain

Question 16

cartilage damage is side effect of

Answer 16

quinolones (ciprofloxacin)

Question 17

if C diff pt can’t get oral antibiotic, what tx is recommended

Answer 17

IV metronidazole

Question 18

rebound and guarding–if positive, could be sign of

Answer 18

peritonitis

Question 19

pathogenesis of C diff

Answer 19

toxin binds to brush border and causes watery diarrhea

Question 20

tx of C diff reommendations

Answer 20

initial episode (mild/moderate)-metronidazole

initial episode (severe)-vancomycin

initial episode (severe, complicated like if had hypotension or shock, ileus, megacolon)-vancomycin plus metronidazole

first recurrence-same as for initial

second recurrence-vancomycin

Question 21

loperamide, diphenoxylate

Answer 21

antidiarrheal

Question 22

how does rehydration work for viral diarrhea?

Answer 22

if you consume Na and glucose, water will follow

Question 23

differential for acute bloody diarrhea

Answer 23

infectious (bacteria)

non-infectious (UC, Crohn’s)

Question 24

what’s the problem with opiod use in diarrhea pt?

Answer 24

can cause constipation

Question 25

diarrhea-possible empiric

Answer 25

ciprofloxacin

Question 26

pseudoappendicitis

Answer 26

Campylobacter

Question 27

acute, non-toxic appearing, non bloody diarrhea–is testing needed?

Answer 27

no

Question 28

when should you order stool culture

Answer 28

severely ill
outbreaks
require hospitalization
immunocompromised
co-morbdities (IBD)

Question 29

travelers’ diarrhea–empiric therapy is?

Answer 29

fluoroquinolone (ciprofloxacin) or TMP-SMZ

Question 30

fever, bloody diarrhea and presence of occult blood or fecal leukocytes in stool–what would you do?

Answer 30

tx with empiric–(except if suspecting EHEC or C diff)

stool test

Question 31

if greater than 8 stools per day, volume depleted, symptoms longer than a week, hospitalized, immunocompromised, what tx should you give?

Answer 31

empiric–fluoroquinolone or azithromycin

Question 32

osmotic diarrhea

Answer 32

electrolyte absorption is not impaired

electrolyte concentrations in stool water are usually low

Question 33

most common cause of secretory diarrhea

Answer 33

infection

Question 34

endocrine tumors–the peptides they produce (VIP, serotonin)-cause osmotic or secretory diarrhea

Answer 34

secretory

Question 35

osmotic gap calculation

Answer 35

serum osm - esmimated stool osmo

stool osm is 2[ [Na] + [K]]

Question 36

osmotic diarrhea-osmotic gap is

Answer 36

over 100 mosm/kg

Question 37

“atypical sprue” symptoms

Answer 37

iron deficiency
osteoporosis (most common non- GI symptom)
dermatitis herpetiformis
IBS
DM type 1
elevated LFTs

can have increased risk of T cell lymphoma

Question 38

non-GI for celiac dis

Answer 38

associations:
Down syndrome
selective IgA deficiency