PUD, GERD, and IBD

Question 1

Tx outline for PUD

Answer 1

1. Relief of symptoms
2. Healing of ulceration
3. Eradicate H. pylori to prevent recurrence

Question 2

MOA antacids

Answer 2

NaHCO3+HCl=NaCl+CO2+H2O, goal is to raise pH >4

Question 3

Ingredients in antacids

Answer 3

Aluminum OH–> constipation
Mg OH–> diarrhea
So, logically, a combination of the 2

Question 4

Dosing and AE of antacids

Answer 4

1 and 3 hr after meal and before bedtime, dont take within 1-2 hrs of other drug, affects other drug absorption

Question 5

MOA of H2 receptor antagonists

Answer 5

Competitive H2 receptor blockers, inhibit all phases of gastric secretion, reduce volume and H concentration of secretions, minimal side effects

Question 6

What are the H2 receptor antagonists and how do they differ?

Answer 6

Cimetidine- least potent, inhibits CYP1A2, 2C19, 2D6, 3A4
ranitidine, nizatidine
Famotidine- most potent, take only once a day, reduces theophylline Cx

Question 7

What are the most potent drugs reducing acid secretion?

Answer 7

PPI

Question 8

MOA omeprazole

Answer 8

PPI, long duration

Question 9

MOA lansoprazole

Answer 9

PPI, less effective in severe esophagitis

Question 10

MOA of PPI

Answer 10

carried by blood to parietal cells and diffuse into secretory canaliculi, trapped by pH protonation due to acidity, bind COVALENTLY to enzyme- noncompetitive–> achlorhydria, new enzymes must be synthesized to overcome

Question 11

What are the cytoprotective agents?

Answer 11

bismuth subsalicylate, sucralfate

Question 12

MOA bismuth

Answer 12

enhances secretion of mucus and HCO3, inhibits pepsin activity, chelates with proteins to form protective barrier against acid and pepsin, inhibits H. pylori, absorbs etiological factors

Question 13

MOA sucrasulfate

Answer 13

sticky viscous gel that adheres to gastric epithelial cells to protect them from acid and pepsin, only one requiring acid pH for max activity

Question 14

When may you use either bismuth or sucrasulfate?

Answer 14

Bismuth: prevent traveler’s diarrhea
Sucrasulfate: H2 or PPI-induced pneumonia in bedridden pt, any chronically bedridden pt

Question 15

What antibiotics are used in the eradication of H. pylori? What are their MOA?

Answer 15

Clarithromycin: macrolide that inhibits protein synthesis
Amoxicillin: effective in G-
Metronidazole: effective against obligate anaerobes
Furazolidine: nitrofuran antibiotic and antiprotozoal

Question 16

Tx regimen for H. pylori

Answer 16

Antibiotics given as multi-drug to prevent resistance. Biggest primary resistance problem is in metronidazole

Question 17

How do you treat the component of GERD associated with GI contents ready to reflux?

Answer 17

Postural and diuretic therapy- lose weight, low fat diet, decrease size of meal, bed elevation

Question 18

How do you treat the compromised LES portion of GERD?

Answer 18

use prokinetic, antisecretory drugs

Question 19

MOA of metochlopramide

Answer 19

prokinetic used in GERD: D2 receptor blockers and weak 5-HT4 agonists–> stimulate GI smooth muscle, increase amplitude of esophageal contractions, accelerate gastric emptying, increase LES pressure

Question 20

Metochlopramide AE

Answer 20

central dopaminergic antagonism- tardive dyskinesia, use short term!