PHARM_PEPTICULCER/GERD

Question 1

what type of acetylcholine receptors are found on parietal cells which when activated promote acid secretion?

Answer 1

M3

Question 2

both gastrin and the M3 receptor act through which type of G protein to promote acid secretion?

Answer 2

Gq

Question 3

Histamine acts through what kind of G protein to activate adenylate cyclase and promote acid secretion?

Answer 3

Gs

Question 4

somatostatin and prostaglandins act through what kind of G protein to inhibit adenylate cyclase and thus inhibit acid secretion?

Answer 4

Gi

Question 5

what is the primary etiology of peptic ulcer disease?

Answer 5

H. Pylori

Question 6

how can you diagnose an H. pylori infection?

Answer 6

blood antibody test or urea breath test

Question 7

what are the 3 major overall goals for the treatment of peptic ulcer disease?

Answer 7

1. eradication of H. pylori (abx-tetracycline, clarithromycin, metronidazole)
2. relief of symptoms (antisecretory agents, antacids)
3. healing of ulcerations (prostaglandin agonists, bismuth, sucrasulfate)

Question 8

MOA of antacids

Answer 8

neutralize gastric acid in the stomach

Question 9

how high do you need to get the pH if you want to prevent the transformation of pepsinogen to pepsin?

Answer 9

pH >4

Question 10

what are the 3 main ingredients in antacids?

Answer 10

aluminum hydroxides
magnesium hydroxids
calcium carbonate

Question 11

aluminum hydroxides can have what side effect?

Answer 11

constipation

Question 12

magnesium hydroxides can have what adverse effect?

Answer 12

diarrhea

Question 13

what are the therapeutic uses of antacids?

Answer 13

simple dyspepsia

adjuncts to primary therapy w/ H2 blockers or PPIs

Question 14

when should you take antacids for them to be most effective?

Answer 14

1-3 hrs after a meal and at bedtime

Question 15

H2 receptor antagonists MOA

Answer 15

highly selective competitive inhibitor of H2 receptor

• inhibit basal, food-stimulated, and nocturnal gastric acid secretion
• reduce both volume and concentration of acid secretion

Question 16

name the most potent h2 receptor antagonist?

Answer 16

famotidine

Question 17

how often does famotidine need to be administered?

Answer 17

once daily because it has a long half life

Question 18

what if the only notable side effect of cimetidine?

Answer 18

inhibits CYP450

Question 19

PPI MOA?

Answer 19

noncompetitive irreversible inhibitor of the H+/K+ ATPase enzyme
result–>achlorhydria-all gastric acid secretion is blocked

Question 20

which 2 PPIs are effective orally b/c they have a long duration of action and are more powerful?

Answer 20

omeprazole & esomeprazole

Question 21

which PPI is metabolized to a much lower extent by the cytochrome P450 system?

Answer 21

rabeprazole

Question 22

how do the PPIs effectively reach their target tissue?

Answer 22

has enteric coating

• in neutral pH the PPI prodrug is stable
• lipid solubility permits absorption
• then carried by blood and diffuse into the secretory canaliculi, where the acid pH causes protonation and trapping of the drug near the proton pump

Question 23

what are the clinical indications for PPIs?

Answer 23

short term treatment of PUD, management of ZES & in refractory gastric, esophageal and duodenal ulcers
-manage symptoms of GERD

Question 24

how does bismuth subsalicylate work?

Answer 24

enhances secretion of mucus & bicarb

• inhibits pepsin activity
• chelates w/ proteins at the base of the ulcer crater and forms a protective barrier against acid and pepsin
• effective treatment of traveler’s diarrhea

Question 25

how does sucralfate work>

Answer 25

forms sticky viscous gel that adheres to gastric epithelial cells protecting them from acid and pepsin

Question 26

___________is the only agent in its calss that requires an acidic pH for its maximal activity

Answer 26

sucralfate

Question 27

when does sucralfate need to be given to promote gastric healing?

Answer 27

given 1 hr before meals and at bedtime

Question 28

which drug is used in H2-blocker or PPI-induced pneumonia in bedridden pts?

Answer 28

sucralfate | -when stomach becomes too basic this can reintroduce harmful bacteria

Question 29

how does metochloparmide work?

Answer 29

dopamine-2 receptor blockers | -w/i GI tract blocking D2 receptors increases the local release of ACh via 5HT4-R agonism

Question 30

name the 5 abx that are used to eradicate H. pylori

Answer 30

1. clarithromycin 2. amoxicillin 3. tetracycline-2nd line 4. metronidazole 5. furazolidine-nitrofuran antibacterial & antiprotozoal

Question 31

what are 2 conditions that cause a reflux episode to occur?

Answer 31

1. GI contents must be ready to reflux | 2. the anti-reflux mech. at the LES is compromised

Question 32

name the 5 aspects of postural & dietary therapy of GERD?

Answer 32

1. decrease gastric contents (size of meal) 2. decrease weight 3. bed elevation 4. low fat diet 5. avoid coffee, peppermint

Question 33

what are the pharmacological actions of the dopamine-2 receptor blockers?

Answer 33

stimulates GI smooth muscle increases amplitude of esophageal contractions accelerates gastric emptying increases LES pressure MAIN ANTIREFLUX= ENHANCED GASTRIC EMPTYING

Question 34

what are some of the side effects of dopamine-2 receptor blockers?

Answer 34

related to central dopaminergic antagonism like tardive dyskinesia -prescribe for 1-2 wks only

Question 35

what are the 2 classes of antisecretory drugs used to treat GERD?

Answer 35

H2 receptor blockers | proton pump inhibitors