Drugs Used for Peptic Ulcer disease

Question 1

Proton Pump Inhibitors

Answer 1

Omeprazole
Lansoprazole
Pantoprazole

Question 2

MOA of Proton Pump Inhibitors

Answer 2

Irreversible inhibition of proton pump H+/K+ ATPase (final step in gastric secretion from parietal cells) → inhibit basal and stimulated acid secretion

Question 3

PK of PPI

Answer 3

Prodrug, taken orally
Rapidly absorbed in the intestines, long duration of action
Metabolised in the liver by CYP450
Activated in acidic medium

Given 1 hour before meals or 2 hours after meals

Question 4

Clinical Use of PPI

Answer 4

Zollinger Ellison Syndrome (drug of choice), severe peptic ulcer, reflux esophagitis

Question 5

AE of PPI

Answer 5

GIT disturbances:
nausea, vomiting, diarrhoea ;
Hypergastrinemia that lead to gastric hyperplasia ;
Increased bacterial flora

Question 6

What are the H2 Receptor Inhibitor

Answer 6

Cimetidine (older version)
Ranitidine (new version)

Question 7

MOA of H2 Receptor inhibitor

Answer 7

Competitively and reversibly block H2 receptor on parietal cells → adenylyl cyclase not activated → protein kinase not activated → inhibits histamine induced gastric secretions
This reduces basal and food stimulated gastric secretions and reduces pepsin activity.
Promote mucosal healing and decrease pain

Question 8

PK of H2 receptor Inhibitor

Answer 8

Absorbed orally, given before meals
Metabolised in the liver by CYP450
Excreted in urine
Can cross placenta and excreted in milk

Question 9

Clinical Use of H2 Receptor Inhibitor

Answer 9

Only used when patients cannot tolerate PPIs
Duodenal ulcers, reflux esophagitis, ZES

Question 10

AE of H2 Receptor Inhibito

Answer 10

Nausea, vomiting,
gynecomastia, impotence, galactorrhea
CNS (if cross BBB): headache, dizziness, confusion
CVS: bradycardia, hypotension
Renal/hepatic dysfunction in elderly

Question 11

What are the Anticholinergic Drugs

Answer 11

Pirenzepine

Question 12

What is the MOA of Pirenzepine

Answer 12

Blocks muscarinic M1 receptors on parietal cells → no Ca2+ → protein kinase not activated → PP not activated → inhibits gastric acid secretion

Question 13

Clinical Use of Pirenzepine

Answer 13

Used together with H2 receptor blockers
Decrease pain in peptic ulcer (spasmolytic effect)

Question 14

Antacids

Answer 14

Sodium Bicarbonate
Calcium Carbonate
(Aluminium OH + Magnesium OH) Longer duration of action

Question 15

MOA of Antacids

Answer 15

When antacid bind to HCl → increases the pH → neutralises gastric acid and inhibits pepsin

Question 16

Clinical uses of Antacids

Answer 16

Used to relieve pain from peptic ulcer and dyspepsia

Question 17

AE of Sodium Bicarbonate

Answer 17

Rebound hyperacidity, stomach distension, pain, salt and water retention, systemic alkalosis

Stomach distention due to liberation of CO2

Question 18

AE of Calcium Carbonate

Answer 18

Stomach distension, hypercalcemia, rebound hyperacidity, milk alkali syndrome

Question 19

AE of Al and Mg hydroxides

Answer 19

No stomach distension and rebound hyperacidity
Constipation, diarrhoea, CNS depression, renal failure

*** Decreases the absorption of tetracycline, digoxin and iron

Question 20

Drugs for mucosal Protective Agent

Answer 20

Sucrose octaphosphate + Al2(OH)3 (Sucralfate)
Prostaglandin Analogues (Misoprostol)
Colloidal Bismuth (Bismuth)

Question 21

MOA of Sucralfate

Answer 21

In acidic conditions, sucralfate dissociates into sucrose octaphosphate and an antacid
SO binds to positively charged protein molecules (coats the ulcer) → inhibits pepsin → promotes healing

Question 22

PK of Sucralfate

Answer 22

Orally, poor systemic absorption
Recommended to take on an empty stomach
Excreted in faeces

Question 23

Clinical use of Sucralfate

Answer 23

Benign gastric and duodenal ulcers, chronic gastritis
Stimulates mucosal protective mechanisms by secreting mucus and bicarbonates

Question 24

AE of Sucralfate

Answer 24

Constipation, dry mouth

Do not co-administer with H2 blockers
Interferes with absorption of tetracycline, theophylline and tricyclic antidepressants

Question 25

MOA of Misoprostol

Answer 25

Decreases HCl secretion,
increases mucus and bicarbonate secretion, increases blood flow of mucosa → heal ulcer

Question 26

PK of Misoprostol

Answer 26

Orally
Excreted in urine

Question 27

Clinical uses of Misoprostol

Answer 27

Prevention of NSAID
induced peptic ulcer

Question 28

AE of Misoprostol

Answer 28

Abdominal cramp, diarrhoea, uterine contraction, dysmenorrhea, abortion

DO NOT GIVE During Pregnancy

Question 29

MOA of Bismuth

Answer 29

Drug forms a precipitate with mucous → covers the ulcer with a protective coat → promote healing of ulcer
Decreases pepsin activity and increases mucus and HCO3- secretion
Has bactericidal effect

Question 30

clinical Use of Bismuth

Answer 30

Used in triple therapy in H. pylori eradication
Benign gastric and duodenal ulcer
Traveller’s diarrhoea

Question 31

AE of Bismuth

Answer 31

Black stool, teeth discolouration, encephalopathy seen in renal dysfunction

Question 32

triple therapy used for H.Pylori

Answer 32

1 PPI ( Omeprazol)
2 Antibacterial ( Clarithromycin, amoxicillin )

Question 33

Quadruple therapy for H. Pylori

Answer 33

Metronidazole/omeprazole
Amoxicillin, tetracycline
Bismuth