Drugs Employed in GI Disease 1

Question 1

the 2 causes for ulcers

Answer 1

increased acid production and decreased mucosal resistance

Question 2

3 interventions for ulcers

Answer 2

1. neutralize acid
2. decrease acid production
3. increase mucosal resistance

Question 3

calcium carbonate

Answer 3

antacid. reacts w/ HCl to make calcium chloride and carbonic acid. side effect is constipation. use in combo with magnesium compounds

Question 4

sodium bicarbonate

Answer 4

antacid. rarely used because of systemic alkalosis. high sodium content

Question 5

magnesium hydroxide/magnesium carbonate

Answer 5

antacid. may cause magnesium toxicity in presence of renal disease. adverse effects include diarrhea. can cause bradycardia with renal problems.

Question 6

aluminum hydroxide

Answer 6

antacid. combines with HCl to make aluminum chloride and water. aluminum Cl -> aluminum phosphate which cant be absorbed. doesnt disturb serum electrolyte or pH. useful in renal failure patients. may have protective effect on mucosa. causes constipation

Question 7

simethicone

Answer 7

defoaming agent in antacids. decreases gas bubbles/bloating

Question 8

sodium

Answer 8

used with antacids. small amounts, but can cause concern in patients with edema and hypertension.

Question 9

anticholinergic agents effect

Answer 9

vagotomy type of effect. reduction of HCl secretion, spasmolytic effect. adverse effects include dry mouth, blurry vision, atony of bladder, constipation, drowsiness, confusion.

Question 10

anticholinergic drugs + when you take them

Answer 10

atropine, propantheline, dicyclomine. administered 30 minutes before meals and at bedtime.

Question 11

blockade of histamine H2 receptor

Answer 11

lower acid secretion by blocking H2 histamine receptors on parietal cells. decrease basal and food stimulated acid secretion. dont need to be given in relationship to meals

Question 12

H2 receptor antagonists list

Answer 12

cimetidine, ranitidine, famotidine, nizatidine. inhibi 50-80% of 24 hour acid secretion.

Question 13

other use for H2 receptor antagonists

Answer 13

can be used prophylactically to decrease stress ulcers in ICU and burn patients.

Question 14

what happens if you abruptly stop h2 blockers?

Answer 14

hyperproduction of acid! ween off slowly

Question 15

H2 blocker adverse effects

Answer 15

messes with p450 so can interfere with metabolism of other drugs. headache, lethargy, confusion, depression. severe side effects uncommon

Question 16

list the 6 H/K ATPase inhibitors (proton pump inhibitors)

Answer 16

omeprazole, lansoprazole, rabeprazole, esomeprazole, pantoprazole, dexlansoprazole

Question 17

which proton pump inhibitors can be given IV

Answer 17

pantoprazole. doesn’t mess with p450.

Question 18

proton pump inhibitor mechanism of action

Answer 18

accumulate selectively in the highly acid environment of the canniliculus. protonated to a reactive thiophillic sulfenamide that binds to cysteine 813 in the alpha subunit of the enzyme. non competitive inhibitors. better pain relief and faster ulcer healing rates than with H2 antagonists. will heal H2 refractory ulcers

Question 19

adverse effects of PPIs

Answer 19

headache, gynecomastia, inhibition of P450, gastric hyperplasia possible in long term stuff.

Question 20

factors impairing mucosal resistance to acid

Answer 20

smoking, genetics, stress, NSAIDs, H. pylori

Question 21

bismuth salts

Answer 21

in acid environment it forms crystals that precipitate on the ulcer crater. lower ulcer recurrence rate than with h2 antagonists

Question 22

sucralfate

Answer 22

aluminum hydroxide complex, activates in acid environment, binds to ulcerated tissue. as effective as H2 antagonists.

Question 23

what type of ulcers are prostaglandin E2 analogs

Answer 23

used in people with NSAID ulcers, because duodenal ulcer patients already hyperproduce E2 prostaglandins

Question 24

misoprostol

Answer 24

prostaglandin E2 analog. decrease acid production, increase mucous and bicarb secretion. less effective than H2 blockers when used solo. approved for prevention of NSAID ulcers. can cause diarrhea, dont use in pregnant bitches!

Question 25

preferred therapies for H. pylori infection

Answer 25

twice a day PPI or ranitidine bismuth citrate triple therapies (PPI or bismuth + 2 of antobiotics)

quadruple therapy: PPI twice a day, tetracycline, bismuth, metronidazole