Drugs used for treatment of Peptic ulcer

Question 1

Omeprazole

Answer 1

MOA: irreversible proton pump inhibitor (H+/K+ ATPase), prevents HCl secretion

Sulfenamide in acidic medium

inactivated if combined with H+ receptor blockers

Question 2

H2 receptor blockers (Cimetidine, Ranitidine, Famotidine, Nizatidine)

Answer 2

MOA: competitively binds to H+ receptors, prevents gastric acid secretion

reserved for patients unable to tolerate proton pump inhibitors

Question 3

Pirenzepine

Answer 3

MOA: binds to M1 receptors on parietal cells (not M3, unknown reason)
- prevents gastric acid secretion
- has spasmolytic effect, used with H2 receptor blockers

Question 4

Sodium Bicarbonate

Answer 4

MOA: antacids, neutralizes HCl, inhibits pepsin

can lead to rebound hyperacidity (CO2), stomach distention (CO2) salt and water retention, systemic alkalosis

Question 5

Calcium Carbonate

Answer 5

MOA: antacids, neutralizes HCl, inhibits pepsin

can lead to rebound hyperacidity (CO2), stomach distention (CO2) hypercalcemia

Question 6

Aluminium Hydroxide + Magnesium Hydroxide

Answer 6

MOA: longer duration of action, no rebound hyperacidity but still neutralizes HCl, absorbs pepsin

Al(OH)3 causes constipation
Mg(OH)3 causes diarrhea

Question 7

H.pylori eradication

Answer 7

Triple Therapy (1 proton pump inhibitor + 2 antibiotics)
- omeprazole + clarithromycin, amoxicillin

Quadruple therapy ( 1 proton pump inhibitor + 2 antibiotics + bismuth compounds)

H.pylori increases acidity, so increasing pH is important

Question 8

Sucralfate

Answer 8

MOA: sucralfate dissociates into sucrose octaphosphate+ aluminium hydroxide

sucrose octaphosphate binds with protein molecules found in damaged mucosa
- protects ulcer healing
- inhibits pepsin
- stimulates mucosal protective mechanisms (mucus and bicarbonate secretion)

Question 9

Misoprostol (prostaglandin analogue)

Answer 9

MOA: decrease HCl secretion, increase mucus and bicarbonate secretion, increase blood flow of mucosa