GI 2 (Gastric Acid)

Question 1

Cimetidine

Answer 1

H2 Receptor Antagonist

Adverse Effects:
- Gynaecomastia
- Galactorrhea
- Decreased Sexual Function

• Thrombocytopenia

Question 2

Ranitidine

Answer 2

H2 Receptor Antagonist

Adverse:
- Thrombocytopenia

Question 3

Nizaridine

Answer 3

H2 Receptor Antagonist

Adverse:
- Thrombocytopenia

Question 4

Famotidine

Answer 4

H2 Receptor Antagonist

Adverse:
- Thrombocytopenia

Question 5

H2 Receptor Antagonist
- MOA:

Answer 5

Antagonize H2 Receptors
= Decrease Parietal Cells cAMP levels
= Inhibits Gastric Acid secretion

• Also heals ulcers

Question 6

H2 Receptor Antagonist
- Adverse Effects:

Answer 6

Cimetidine causes:
- Gynaecomastia
–> Breast development in males
- Galactorrhea
–> Lactation in males
- Decrease in male sexual activity (Rare)

Thrombocytopenia
- Decrease platelet count

Question 7

Proton Pump Inhibitors
- MOA

Answer 7

Weak Base that builds up in the canaliculi (where all the proton pumps are)
- Binds irreversibly to proton pumps
= Reduces H+ pumped into stomach lumen

Question 8

Proton Pump Inhibitors
- Adverse Effects

Answer 8

Hypergastrinemia (Proton pump inhibitors masks symptoms of gastric cancer)
- No secretion of acid
= Negative Feedback Loop
= G-Cells try to produce more acid
= Rebound Hypergastrinemia

Question 9

Misoprostol

Answer 9

Prostaglandin E1 Analogue
- Cytoprotectants
- Decrease Gastric Secretion
- Promotes healing of ulcers

Question 10

Misoprostol
- MOA

Answer 10

• Acts on ECL Cell’s Prostaglandin EP(2/3) Receptors to inhibit food induced gastric acid secretion
• Contributes to maintenance of mucosal barrier
  –> EP4 Receptor = Mucin
  –> EP(1/2) = Bicarbonate

Question 11

Misoprostol
- Adverse Effects

Answer 11

Uterine Contractions
- Avoid in pregnancy

Question 12

Antacids
- MOA

Answer 12

Neutralize gastric acid secretions which inhibits peptic enzymes

Question 13

Antacids
- Gastric Ulcers vs Duodenal Ulcers

Answer 13

More effective at treating Duodenal Ulcers

Question 14

Magnesium Hydroxide (Magnesium Salt)

Answer 14

Antacid
- Forms Magnesium Chloride in stomach
- Causes Diarrhea

Question 15

Aluminum Hydroxide Gel
(Aluminium Salt)

Answer 15

Antacid
- Forms Aluminium Chloride in stomach
- Causes Constipation

Question 16

Simeticone

Answer 16

Given with antacids
- Anti-foaming agent that relieves bloating caused by Carbonate Antacids

Question 17

Bismuth Chelate

Answer 17

Cytoprotectants
- Toxic to bacillus and prevents adherence of H. pylori gastric mucosa

Question 18

Bismuth Chelate
- MOA

Answer 18

• Forms protective barrier over ulcer
• Enhances secretions of prostaglandins, mucus, bicarbonate
• Inhibits Bacterial proteolytic enzyme

Question 19

Bismuth Chelate
- Adverse Effects

Answer 19

• Blackening of tongue and feces
• Tinnitus
• If Renal Excretion is Impaired
  = Encephalopathy (Reye’s Syndrome)
  –> Brain Damage

Question 20

Sucralfate

Answer 20

Cytoprotectants
- Made up of Aluminium Hydroxide + Sulfated Sucrose

Question 21

Sucralfate
- MOA

Answer 21

Releases aluminium when exposed to acid forming a viscous paste
–> Paste binds to positive charged proteins in ulcer
= Creates protective barrier

• Pepsin prevents degradation of mucus
• Stimulates secretion of mucus, bicarbonate, and prostaglandins from mucosa

Question 22

How to treat H. Pylori

Answer 22

Triple Therapy with Antibiotics + Proton Pump Inhibitor

Question 23

Omeprazole

Answer 23

Proton Pump Inhibitors

Question 24

Esomeprazole

Answer 24

Proton Pump Inhibitors

Question 25

Lansoprazole

Answer 25

Proton Pump Inhibitors

Question 26

Pantoprazole

Answer 26

Proton Pump Inhibitors

Question 27

Rabeprazole

Answer 27

Proton Pump Inhibitors