Pharm: GIT drugs

Question 1

Major antacids
MOA antacids
Major AE’s

Answer 1

• Weak bases that ract with HCl to form salt/water
  MgOH: diarrhea
  AlOH: constipation, dec PO4
  CaCO3: hyperCa, nephrolithiais, constipation
• Can chelate tetracyclins *

Question 2

What drugs are known chelators of tetracyclins?

Answer 2

Antacids

Question 3

Who are the major H2 antagonists? What are the major uses?

Answer 3

Cimetidine, ranitidine, famotidine, nizatidine

• Acute stress ulcers 2/2 trauma or ICU stay
• Prevent aspiration PNA
• GERD

Question 4

What are the major AE’s of cimetidine? Any involvement of CYP450?

Answer 4

Anti-androgen; confusion in elderly

* Inhibits CYP450

Question 5

DOC treatment of acute stress ulcer (Curling/Cushing)

Answer 5

H2 antagonists

Question 6

MOA PPI’s

Answer 6

Inhibit 100% acid secretion; irreversible inactivation H/K ATPase; transported into parietal cell

Question 7

Uses PPI

Answer 7

GERD, ulcers, MEN1, ZES, H. pylori (with ABX), NSAID-induced ulcers, platelet aggregation/maintenance clots

Question 8

Major AE’s PPI

Answer 8

Hypomagnesemia (increased hip fractures); pancreatitis/hepatotoxicity/TIN-renal

Question 9

Omeprazole inhibits the metabolism of…

Answer 9

Warfarin, clopidogrel, phyytoin, diazepam, cyclosporin

Question 10

ABX used for H. pylori (in addition to PPI)

Answer 10

Clathromycin, amoxicillin

Question 11

Mucosal protection agents

Answer 11

Sucralfate: selectively bind to necrotic tissue = barrier to acid; only works in acidic environment
Bismuth
Misoprostol

Question 12

What is the most important fact about sucralfate?

Answer 12

Only works in acidic environment; requires acid to be activated

Question 13

What are the drugs of choice to prevent gastric ulcer induced by NSAID?

Answer 13

H2 antag, PPI, [Misoprostol]

Question 14

Misoprostol MOA

Answer 14

PGE1 agnoist: mucin, bicarbonate

Question 15

2 cholinomimetic prokinetics, major uses

Answer 15

Neostigmine: colonic pseudoobstruction
Bethanachol: post-op bowel/bladder atony

Question 16

Use of erythromycin as a prokinetic; Major use; AE

Answer 16

Acts on motilin receptor of GIT; increases gastric activity

• Use: gastric emptying before upper GI procedures
• AE: tolerance can develop and lead to gastroparesis

Question 17

Metaclopramide (2 MOA), major AE

Answer 17

5-HT3, D2 Antag: anti-emetic
5-HT4 Ag: prokinetic (mucarinic)

• DM/post-op gastroparesis, GERD, constipation
• AE: anti-dopaminergic activity: sedation, diarrhea, Parkinson’s

Question 18

Cisapride (MOA), major AE

Answer 18

5-HT4 Agonist: stimulates ACh; gastroparesis/gerd/constipation
AE: arrhythmias

Question 19

DOC CINV

Answer 19

Dexamethasone/methylprednisone + odanestron; aprepitant

Question 20

Classes of drugs used as anti-emetics

Answer 20

1. 5-HT3 Antag: Odanestron
2. H1 Antag: Diphendydramine, Cyclizine, Meclazine
3. Antimuscarinic: Scopalamine
4. CS: Dexamethasone
5. D2 Antag: Prochlorperazine
6. NK1 Antag: Aprepitant
7. Benzamide: Metoclopramide
8. Marijuana: Dronabinol
9. Benzo’s: Lerzepam, alaprazolan, diazepam

Question 21

IBD Treatments

Answer 21

Sulfasalzine: Il-1, TNF (degraded into 5-ASA [IBD] and sulfapyridine)
6MP + MTZ: 6MP=apoptosis; MTX=DHFR
Infliximab/Adalimub/Natalizumab: TNF-alpha; integrins