GI

Question 1

esomeprazole, omeprazole, inasoprazole, dexlansoprazole, pantoprazole, rabeprazole

Answer 1

PPI

• Benzimidazole compounds irreversibly inhibit parietal cell proton pump (H/K ATPase)
  
  • The inhibition persists after stoping the drug (because its an irreversible inhibitor) - have to wait for new pumps to be made
• They are pro drugs that are inactive at neutral pH (need acid to be active)
  
  • Take with meals = food -> more gastric secretion
  • These drugs are unstable at low pH - enteric coating (only disolves in alkaline pH) to get past stomach - absorbed in intestines -> carried in circulation to parietal cells where it acts
  • The drug acts at the intracellular canaliculi which is upstream from the proton pump (this is how it stays chornically active even when it shuts down gastric acid secretion ) (it still needs acidic envionrment to work)
• Drugs
  
  • Esomeprazole, omeprazole, lansoprazole, dexlansoprazole, pantroprazole, rabeprazole
• Curretnly the most effective drugs for suppressing gastric acid secretion because gastric response to all stimuli is inhibited\
• Can give a single daily dose
• AE
  
  • GI effects (nausea, colic, flatulence, constipation, diarrhea)
  • CNS effects (headaches, dizziness, somnolence)
  • Skin rashes
  • With prolonged use diarrhea often occurs due to GIT bacterial overgrowth from removal of natural acid barrier
  • Hypergastrinemia can happen
• Hepatic metabolism with negligible renal clearance
• Uses
  
  • Promote peptic ulcer healing and prevent recurrence
  • Effective in patienst unresponsive to H2 antagonists
  • More effective than H2 antagonists for GERD or NSAID induced peptic ulcers

Question 2

cimetidine, famotidine, nizatidine, ranitidine

Answer 2

H2 receptor antagonists

• All are over the counter structural histamine analogs -> block H2 receptors selectivlty to reduce gastric acid and pepsin secretion
  
  • Doesn’t affect H/K ATPase, H1 or any other receptors
  • Best at inhibiting nocturnal secretion (largely driven by histamine)
• AE
  
  • Diarrhea, headaches, fatigue, myalgias, constipation, bradycardia
  • Don’t give to pregannt women or nursing women - they can cross placenta and get into milk
  • Mental changes: confusion, hallucinations and agitation may occur with IV administration in patents who are old or have renal or hepatic dysfunction
  • Cimetidine can cuase gynecomastia or impotence in men
    
    • Cimetidine inhibits dihydrotestosterone to androgen receptors
    • Can also interfere with CYP 450 pathways for other drugs
  • They stop formation of protons at the canaliculi of parietal cells = less activation of PPDs
• Uses
  
  • All equally effective for healing and preventing recurrence of PUD
  • Given once a day at bed time
  • We have better drugs so they are used less now
  • Can be combined with antibiotics and bismuth for treatment of H pylori

Question 3

aluminum hydroxide

Answer 3

antacid

• Aluminum hydroxide, calcium carbonate, combination aluminum hydroxide and magnesium hydroxide
• AE
  
  • Aluminum hydroxide - produces constipation
    *

Question 4

magnesium hydroxide

Answer 4

antacid

produces diarrhea

Question 5

calcium carbonate

Answer 5

tums and others - antacids

doesnt really cuase constipation or diarrhea

Question 6

combination aluminum hydroxide and magnesium hydroxide

Answer 6

antacid

aluminum cuases constipation and the magnesium cuases diarrhea - put them together - they cancel eachother out

Question 7

sucralfate

Answer 7

mucosal protective agent

• Binds selectively to necrotic ulcer tissue and acts as a barier
  
  • Polymerizes to produce a viscous gel that adheres to the epi cells
  • Effective in healing duodenal ulcers
• AE
  
  • Constipation = most common
• Requires acidic pH for activation - don’t give with antacids, H2 antagonists or PPIs

Question 8

misoprostol

Answer 8

mucosal protective agent

• Misoprostol - Methyl analog of PGE1
  
  • Binds to PG receptors on parietal cells to inhibit acid secretion
    
    • NSAIDs inhibit production of PG - but you can replace the PG in the stomach to stop the ulcers from forming
  • Use
    
    • Prevent NSAIDs ulcers from forming
  • AE
    
    • Diarrhea and abdominal pain
  • May cause abortion by stimulating uterine contractions

Question 9

bismuth subsalicylate

Answer 9

peto-bismol

• Bismuth subsalicylate (pepto bismol) - colloidal bismuth
  
  • Protective coating of ulcers - precipitates out in the stomach forming a lining on the stomach
    
    • The precipitate is black - can turn your tongue black
  • Antibacteiral agaisnt H pylori

Question 10

how to treat H pylori

Answer 10

clarithromycin

amoxicillin

PPI

Question 11

glycerin

Answer 11

osmotic laxatives - saline laxatives - nondigestible sugars and alcohols

• Glycerin -
  
  • Trihydroxy alcohol that acts as a lubricant and osmotic agent
• Lactulose, sorbitol, mannitol - non absorbable sugars
• Saline laxatives - non absorbable salts containing magnesium cations (mag citrate) or phosphate anions (sodium phosphate)
  
  • Have a very bitter taste - people commonly add to fuit juices
  • Avoid in patients with
    
    • Renal insufficiency - theses patients already have issues with water balance
    • Heart disease
    • Electrolyte imbalance
    • Diuretic drug co treatment

Question 12

lactulose

Answer 12

osmotic laxatives - saline laxatives - nondigestible sugars and alcohols

Question 13

sorbitol

Answer 13

osmotic laxatives - saline laxatives - nondigestible sugars and alcohols

Question 14

minnitol-polyethylene glycol

Answer 14

osmotic laxatives - saline laxatives - nondigestible sugars and alcohols

Question 15

(PEG) - electrolyte solutions

Answer 15

• Poorly absorbed and retain added water by osmotic pressure
• Mixtures of: sodium sulfate, sodium bicarbonate, sodium chloride, potassium chloride in isotonic solution
• Used in colonoscopy preparation - drink 3-4 liters over 3-4 hours to produce watery diarrhea and remove solid wastes

Question 16

bisacodyl

Answer 16

stimulant or irritant laxatives

• Bisacodyl
  
  • Enteric coated tablets taken at bedtime to take effect next morning
    
    • Don’t chew = break the capsule

Question 17

cascara sagrada

Answer 17

stimulant or irritant laxatives

• Anthraquinones like: aloe, cascara sagrada, or senna
  
  • Poorly absorbed in small intestine and require activation in the colon (laxative effects 6-12 hours later)
  • Long term use can cuase melanomic pigmentation of colonic mucosa and cathartic colon (colon dilated and ahaustral)

Question 18

senna

Answer 18

stimulant or irritant laxatives

• Anthraquinones like: aloe, cascara sagrada, or senna
  
  • Poorly absorbed in small intestine and require activation in the colon (laxative effects 6-12 hours later)
  • Long term use can cuase melanomic pigmentation of colonic mucosa and cathartic colon (colon dilated and ahaustral)

Question 19

ricinoleic acid

Answer 19

stimulant or irritant laxatives (castor oil)

• Local irritant -> increases intestinal secretion and motility
• Now seldom used due to unpleasant taste and toxic potential

Question 20

methylcellulose

Answer 20

bulk forming laxatives

contain lots of soluble fiber and other stuff to give you more material in feces

Methylcellulose, lactulose and polycarbophil

Still have to keep hydrated - need water to move everything along

Question 21

lactulose

Answer 21

bulk forming laxatives

contain lots of soluble fiber and other stuff to give you more material in feces

Methylcellulose, lactulose and polycarbophil

Still have to keep hydrated - need water to move everything along

Question 22

polycarbophil

Answer 22

bulk forming laxatives

contain lots of soluble fiber and other stuff to give you more material in feces

Methylcellulose, lactulose and polycarbophil

Still have to keep hydrated - need water to move everything along

Question 23

mineral oil

Answer 23

stool softener

• Agents that soften stools and facilitate expulsion
• Given orally or rectally
• Include: mineral oil, glycerin suppositories, docusate sodium
• Docusate is often prescribed to prevent straining in hospitalized patienst
  
  • Also can be given with opiates to prevent constipation

Question 24

glycerin suppositories

Answer 24

stool softener

• Agents that soften stools and facilitate expulsion
• Given orally or rectally
• Include: mineral oil, glycerin suppositories, docusate sodium
• Docusate is often prescribed to prevent straining in hospitalized patienst
  
  • Also can be given with opiates to prevent constipation

Question 25

docusate

Answer 25

stool softener * Agents that soften stools and facilitate expulsion * Given orally or rectally * Include: mineral oil, glycerin suppositories, docusate sodium * Docusate is often prescribed to prevent straining in hospitalized patienst * Also can be given with opiates to prevent constipation

Question 26

loperamide

Answer 26

antidiarrheal drug * Loperamide, difenoxin and diphenoxylate - these are basically non effective opioids - give constipation but don’t relieve pain * Act on intestinal opioid receptors -\> inhibit ACH release -\> decreases motility * Loperamide * Effective agasint travelers diarrhea - but need to discontinue if improvemnet doesn’t happen in 48 hours * Can get rebound constipation

Question 27

diphenoxylate

Answer 27

antidiarrheal drug * Loperamide, difenoxin and diphenoxylate - these are basically non effective opioids - give constipation but don’t relieve pain * Act on intestinal opioid receptors -\> inhibit ACH release -\> decreases motility

Question 28

difenoxin

Answer 28

antidiarrheal drug * Loperamide, difenoxin and diphenoxylate - these are basically non effective opioids - give constipation but don’t relieve pain * Act on intestinal opioid receptors -\> inhibit ACH release -\> decreases motility

Question 29

bismuth - subsalicylate

Answer 29

antidiarrheal drug (petobismol) * nhibits intestinal secretions * Management of infectious diarrhea

Question 30

kaolin/pectin

Answer 30

antidiarrheal drug * Kaolin (chalk)/pectin (polymerizing agent) * When you eat this it forms harder stools (because of the chalk)

Question 31

octreotide

Answer 31

antidiarrheal drug * Somatostatin/octreotide - endogenous hormones = reduce motility * Inhibits secretion of: gastrin, cholecystokinin, glucagon, growth hormone, insulin, secretin, pancreatic polypeptide, VIP, and 5-HT * Slows motility and inhibits gallbladder contraction * Reduces portal and splanchnic blood flow * Used more in chronic cases of diarhea (more serious drugs)

Question 32

dimenhydrinate

Answer 32

histamine H1 antagonist * Histamine H1 antagoinists * First generation H1 blockers * Produce sedation and antimuscarnic activity * Prevents motion sickness * Drugs: dimenhydrinate, diphenhydramine, cyclizine, meclizine

Question 33

meclizine

Answer 33

histamine H1 antagonist * Histamine H1 antagoinists * First generation H1 blockers * Produce sedation and antimuscarnic activity * Prevents motion sickness * Drugs: dimenhydrinate, diphenhydramine, cyclizine, meclizine

Question 34

diphenhydramine

Answer 34

histamine H1 antagonist * Histamine H1 antagoinists * First generation H1 blockers * Produce sedation and antimuscarnic activity * Prevents motion sickness * Drugs: dimenhydrinate, diphenhydramine, cyclizine, meclizine

Question 35

cyclizine

Answer 35

histamine H1 antagonist * Histamine H1 antagoinists * First generation H1 blockers * Produce sedation and antimuscarnic activity * Prevents motion sickness * Drugs: dimenhydrinate, diphenhydramine, cyclizine, meclizine

Question 36

metoclopramide

Answer 36

D2 antagonists

Question 37

trimethobenzamide

Answer 37

D2 antagonist

Question 38

ondansetron, granisetron, dolasetron

Answer 38

HT3 antagonists * * Currently used for nausea and vomiting during cancer chemo

Question 39

aprepitant, foaprepitant, rolapitant

Answer 39

NK-1 antagonists

Question 40

chlorpromazine

Answer 40

phenothiazine - antiemetic

Question 41

prochloorperazine

Answer 41

phenothiazine - antiemetic

Question 42

lorazepam

Answer 42

benzodiazepine - antiemetic

Question 43

alprazolam

Answer 43

benzodiazepine - antiemetic

Question 44

tetrahydrocannabinol

Answer 44

marijuana derivative

Question 45

dronabinol

Answer 45

marijuana derivative

Question 46

pancrelipase

Answer 46

pancreastic enzyme replacment * Pancreatic enzyme supplements * Exocrine pancreastic insufficiency caused by cystic fibrosis, chronic pancreastitis, or pancreastic resection * Can lead to steatorrhea, azotorrhea, vitamin malabsorption and weight loss * Supplements * Pancreatin * Pancrelipase * Administed with each meal and snack - need the enzymes to digest the food * High purine content of extracts can lead to hyperuricosuria and renal stones

Question 47

amitriptyline or desipramine

Answer 47

IBS treatment * Tricyclic antidepressants * Low doses of amitriptyline or desipramine * Treatment of abdominal pain

Question 48

dicyclomine or hyoscyamine

Answer 48

IBS treatment * Antispasmodics * Anticholinergic (dicyclomine, hydroscyamine)

Question 49

tegaserod

Answer 49

IBS treatment * 5-HT4 partial agonist * Tegaserod * Emergency treatment only (IBS with constipation) where no alternative exists * Serious cardiovascular events can occur

Question 50

alosetron

Answer 50

* 5-HT3 antagonist * Alosetron * This is if conventional therapy failed * Diarrhea predominant IBS * Serious cardiovascular events can occur IBS treatment

Question 51

eluxadoline

Answer 51

IBS treatment * kappa opioid agonist/ delat opioid antagonist * Eluxadoline * Diarrhea predominant IBS * Reduces neuronal drive on peristalsis * Spasm in sphincter of oddi can result in pancreatitis

Question 52

rifaximin

Answer 52

IBS treatment * Antibiotic * Rifaximin * Diarrhea predominant IBS * Synthetic antibiotic similar to rifampin * May alter bacterial content of GI tract

Question 53

orlistat

Answer 53

antiobesity GI lipase inhibitor reduces absorption of fats since triglycerides are not split tox: flatulence, steatorrhea, fecal incontinence

Question 54

sibutramine

Answer 54

antiobesity SERT and NET inhibitor reduces appetitie Tox: cardiovascular - tachy, hypertension

Question 55

rimonabant

Answer 55

antiobesity CB1 receptor antagonists (canabanoid receptor antag - bascially anti weed) reduces appetitie TOX: depression, anxiety, nausea