GI system week 2: lecture questions Flashcards
which class of antiemetics is ondansetron
a serotonin receptor antagonist
how does ondansetron affect the heart
it can lower the q wave so its contraindicated for those with cardiac issues
which drug class is dexamethosone
it is a glucocorticoid (steroid for fast relief
what are the side effects of dexamethasone if used for a short period of time
literally none
which pathway does metoclopramide block
it blocks the serotonin and dopamine pathways to CTZ (it is a dopamine antagonist)
why does Matoclopramide cause peristalisis
it is a pro kinetic drug, it enhances upper GI in response to acetylcholine
which drug poses a risk for tardive dyskinesia
metroclopramide (its basically muscle spasms)
what is nabilone used for
its a cannabinoid used for chemo
what drug class is dimenhydrinate
it is an antihistamine (gravol)
which pathway does dimenhydrinate block
it blocks the H and M pathway
what are some contraindications of dimenhydrinate
hx of glaucoma, lung disease or difficulty urinating
what is dimenhydrinate typically used for (indications)
motion sickness, post-op drug induced nausea
which drug class is scopolamine
muscarinic antagonist
what is scopolamine best used for
motion sickness (it is anticholinergic)
what are the most common uses for ondansetron
chemo
radiation
anesthesia
viral gastritis
pregnancy
what is dexamethasone typically used for
chemo (also used with ondansetron)
what is metroclopramide most commonly used for
opioid induced nausea
which 2 antiemetics are anticholinergic
scopolamine and dimenhydrinate
how does psyllium work?
it is a laxative that forms bulk (contains polysaccharides and cellulose)
how does lactulose work
it turns into lactic acid in the colon which has osmotic action
how does magnesium hydroxide work
it contains salts which draws water into lumen (osmotic)
how does polyethylene glycol work
it is a non absorbable compound which retains water in the intestinal lumen (osmotic)
which osmotic laxative is appropriate for chronic constipation
polyethylene glycol
which laxative is most appropriate for opioid induced constipation
bisacodyl
how does bisacodyl work
it stimulates peristalsis and increases amount of water and electrolytes in the blowel
how does docusate sodium work
it softens stool through penetration of salt and water
which laxatives take 1-3 days to work
Psyllium, lactulose, docusate sodium
which laxatives take 6-12 hours to work in low doses, and 2-6 hours to work in high doses
magnesium hydroxide and polythelene glycol
which osmotic laxative is bad for the kidneys
magnesium hydroxide
which laxative helps with the excretion of ammonia (good for the liver)
lactulose
how do opioids help with diarrhoea?
they activate opioid receptors in the GI system which slow GI motility
what are the two opioid antidiarrheals
diphenoxylate and loperamide
which antidiarrheal do we add atropine to and why
diphenoxylate because it discourages abuse due to its bad side effects
which antidiarrheal is used to reduce amount of discharge in ileostomy
loperamide (Imodium)
how does bismuth subsalicylate act as an anti diarrhoea
it coats walls of GI tract, binds to bacteria or toxin and removes it though stool
which antidiarrheal may cause dark stool that looks like melena
bismuth subsalicylate
what are the 4 goals of treatment for PUD (pharmacology)
alleviate symptoms, promote healing, prevent complications, prevent reoccurrence
what do H2 receptors do
they’re located in the parietal cells of the stomach, blocking them reduces the volume of gastric juice and decreases concentration of stomach acid
what is the H2 receptor antagonist
Ranitidine
how long does Ranitidine take to work
6-12 weeks to heal gastric and duodenal ulcers
what does omeprazole do (moa)
its a proton pump inhibitor, proton pumps an enzyme that makes gastric acid
how long does omeprazole take to work
it inhibits 97% of acid production in 2 hours
what does it mean when a drug is acid-labile (which drug is this)
omeprazole is an acid-labile drug, meaning its easily destroyed in an acidic environment
because of this capsules for this drug contain coated granules that only dissolve in the duodenum
which two PUD drugs require monitoring for pneumonia
ranitidine and omeprazole
what is dyspepsia
rebound acid hyper secretion, usually caused by omeprazole
how do you remember what sucralfate does
its a bandaid over ulcers
what is sucralfate moa
it creates a mucosal barrier against acid and pepsin to protect against ulcers
how long does sucralfate work for
6 hours
what are three things you need to remember when administering sucralfate
don’t take with other antacids
take on empty stomach
take 30 mins apart from other meds because it might alter absorption
which PUD drug should you use specifically for ulcers caused by chronic NSAID use
Misoprotisol
what is Misoprotisol MOA
it replaces endogenous prostaglandin which suppresses acid production, increases bicarb and mucous secretion, and increases mucosal flow
which PUD should you never take while pregnant
misoprotisol
antacids MOA
they have alkaline properties that raise the pH of the stomach, decreasing pepsin and increasing prostaglandins
which antiemetic causes a prolonged q wave
ondansetron
which two antiemetics are anticholinergic
scopolamine and dimenhydrinate
which antiemetic could cause tardive dyskinesia
metoclopramide
what is tardive dyskinesia
basically causes jerks in your face and tounge that you can’t control
which antiemetic is the best for motion sickness
metoclopramide
what is the fastest working laxative
bisacodyl
which is the laxative used to clean people out before surgery
PEG
which laxative has the most adverse effects
Lactulose
what is ranitidine and what does it do
a histamine 2 receptor agonist, decreases volume of gastric juice
what is sucralfate
band aide over ulcers
what is omeprazole
proton pump inhibitor and inhibits the enzyme that makes gastric acid
