Diarreha TBL Flashcards
bismuth subsalicylate drugs
pepto, kaopeptate
MOA of bismuth subsalicylate
inflammatory prostaglandins stimulate intestinal motility and diarrhea, inhibitors of cyclooxygenase
are antimotility; salicylate component completely absorbed; bismuth may stimulate absorption of
fluids and electrolytes across intestinal wall
SE of bismuth subsalicylate
constipating, high doses, like aspirin, may cause tinnitus; may cause temporary black tongue and
stools
MOA of anti-diarrhea opiods
act on mu opiate receptors in the submucosal and myenteric plexus
anti-diarrhea opiods
loperamide (immodium), diphenoxylate + atropine
shortcomings of anti-diarreha opiods
requires smaller dose of opioids to affect gut than to produce analgesia or euphoria, but physical
dependency still limits clinical use of some drugs; treats symptoms but not underlying cause
prodrug
metabolized to active compound difenoxin
diphenoxylate
use of imodium
acute non-specific diarrhea and chronic diarrhea associate with inflammatory bowel disease
def of acute diarrhea
3+ loose, watery stools within 24 hours
def of chronic diarreha
Episodes of diarrhea lasting more than 14 days
def of dysentery
Blood diarrhea, with visible blood and mucus present in the diarrhea
general cause of bloody diarreha
invasive pathenogen or cytotoxin releasing pathogens
bloody stool with no leukocytes indicates
EHEC
bugs that can cause bloody diarrhea
EHEC, Campylobacter, shigella, salmonalla, C diff
things to look for to asses dehydration
: general appearance, alertness, BP and pulse, postural hypotension, mucous membranes, sunken eyes, skin turgor, capillary refill, JVD, and sunken fontanelle
severe dehydration in kids
(2 or more) abnormally sleepy or lethargic (these are not the same thing!), sunken eyes, drinking poorly or not at all, very slow skin pinch test (>2 seconds)
signs of dehydration in adults
o pulse rate >90 o postural hypotension o supine hypotension and lack of palpable pulse o dry tongue o sunken eyeballs o slow skin pinch test
treatment of diarrhea that has lead to most of the drop in mortality
ORS
main ingredients in ORS
electrolytes, sugar, water
type of ORS best for cholera
rice based ORS
used for rehydration in severe dehydration
lactated ringers, THEN ORS
what NOT to use for rehydration
5% dextrose and 1/4 normal saline
diarrhea less than 6 hrs after exposure could be
preformed toxins of Staph A or b cerus
diarrhea 6-12 hours after exposure could be
preformed toxin of C perfringens or B cerus
bugs that are spread by food outbreak
salmonella, shiga toxin E coli, yersina, cyclospora
waterbourne transmission
crypto, giardia, vibro
seafood and shellfish transmission
vibro, norovirus, salmonella
poultry spread
campylobacer, salmonella
spread by beef, raw seed and sprouts
shiga e coli, ehec
spread from person to person
shigella, rotavirus
can be a result of antibiotic therapy
c diff
MOA of tetracyclines
: bind 30S binding site on ribosome to prevent binding of amino acid-charged tRNA
resistance to tetracyclines
: widespread; development of efflux pumps; formation of ribosomal protection protein that prevent tetracycline binding
MOA of macrolides
reversibly bind 50S ribosomal subunit near the MLSb site
resistance to macrolides
efflux pumps; methylase that adds methyl group to ribosomal binding site to block macrolide binding
MOA of sulfanamides
bacteriostatic inhibitors of folic acid synthesis by competitively inhibiting dihydropteroate synthase
resistance of sulfanamides
; plasma-mediated; decreased intracellular accumulation, increased PABA production by bacteria, or decreased sensitivity to the sulfonamide
MOA of trimethoprim
: selective inhibitor of bacterial DHFR inhibiting folic acid synthesis specifically in bacteria
resistance of trimethoprim
production of dihydrofolate reductase with reduced affinity for the drug
MOA of fluroquinlones
: inhibit topoisomerase II (DNA gyrase) especially in g(-) to block relaxation of supercoiled DNA and topoisomerase IV especially in g(+) to interfere with separation of replicated chromosomal DNA during cell division
resistance of fluroquinilones
decreased intracellular accumulation due to efflux pumps or porins (in g(-)); also changes in sensitivity via point mutations in antibiotic binding regions
DOC for protozoal infections
Metronidazole
SE of metronidazole
o contraindicated with alcohol – causes disulfiram-like reaction
o also contraindicated in CNS disease and pregnancy because can get high concentrations in the CSF
community aquired/traveller’s diarhhea probably
o contraindicated with alcohol – causes disulfiram-like reaction
o also contraindicated in CNS disease and pregnancy because can get high concentrations in the CSF
HUS caused by
E coli (EHEC)
persistant diarrhea, think
EPEC or protozoa
bloody, mucoid diarrhea often with fever
EIEC
poultry and possible GB aftterwards
campylobacter
o There is an acute onset of nausea, vomiting, and diarrhea that may be watery or dysenteric, and fever
salmonella
