Week 5 - Diarrhea Flashcards
define diarrhea
- having 3 or more loose liquid stools per day
- or as having more stools than is normal for that person
what 6 things does diarrhea result from or a combo of
- excess secretions in the GI tract
- malabsorption
- inflammation
- exudate
- invasion
- increased osmotic pressure
what is an example of something that causes excess secretions?
- enterotoxins produced by e.coli which stimulate gut secretion
what does malabsorption cause?
= digestable materials go into the large intestine
- and leads to bacterial growth
how does exudate contribute to diarrhea
- causes increased liquid
give an example of how invasion can cause diarrhea
- dysentry –> an infectious disease that causes inflammation of the lrg intestine and causes bloody diarrhea
describe how inflammation can cause diarrhea
- causes less absorption of water & Na = more leakage of fluids
describe how increased osmotic pressure can lead to diarrhea
- causes water to be drawn into the lumen
what is an example of how increased osmotic pressure leads to diarrhea
- lactase deficiency –> deficiency in enzyme responsible for digestion
- the undigested lactose = increased # of solute particles = increased osmotic pressure
what are GI secretions rich in
- HCO3- and K+
what does diarrhea lead to? (2)
- hypokalemia
- metabolic acidosis
list 5 causes of diarrhea
- infections
- malabsorption
- inflammatory bowel disease
- irritable bowel syndrome
- others
what are some causes of malabsorption (4)
- enzyme deficiencies
- loss of pancreatic secretions
- loss of bile acids
- structural defects
list 4 physiological effects of diarrhea
- loss of HCO3- = metabolic acidosis
- loss of K+ = hypokalemia
- dehydration
- hypovolemic shock
how is metabolic acidosis compensated
- increased resp rate to decrease CO2
how can diarrhea rapidly cause dehydration and hypovolemic shock
- thru loss of consumed & secreted fluid
which two populations are at an increased risk of dehydration & hypovolemic shock r/t diarrhea
- children
- older adults
what are drugs that treat diarrhea called
- antidiarrheals
list 2 categories of antidiarrheals
- absorbents
- antimotility drugs
what is the MOA of absorbents (2)
- coat the walls of the GI tract
- bind to the causative bacteria or toxin so it can be eliminated thru the stool
list 3 examples of absorbents
- bismuth subsalicylate (pepto bismol)
- activated charcoal
- aluminum hydroxide
list 9 side effects of bismuth subsalicyclate
- increased bleeding time
- constipation
- dark stool
- confusion
- twicthing
- hearing loss
- tinnitus
- metallic taste
- blue gums
what are 2 types of antimotility drugs
- anticholinergics
- opiates
what is the MOA of anticholinergics for diarrhea (3)
- decrease intestinal muscle tone
- decrease peristalsis of the GI tract
= slows the movement of fecal matte thru the GI
what is an example of an anticholinergic as an antimotility drug (2)
- belladonna alkaloids (atropine, hyoscyamine)
what is the MOA of opiates for diarrhea (3)
- decrease bowel motility
- relieve rectal spasms
- decrease transit time thru the bowel = more time for water & electrolytes to be absorbed
list 2 uses of opiates
- reduced pain by relief of rectal spasms
- for diarrhea
list 2 examples of opiates as antimotility drugs
- loperamide (Imodium)
- diphenoxylate with atropine (Lomotil)`
what s/e are associated with the belladonna alkyloids
- anticholinergic effect
list 3 types of antibiotics that can be used for H.pylori
- amoxicillin
- clarithromycin
- metronidazole (flagyl)
what s/e are associated with amoxicillin & clarithromycin
- diarrhea
