Foregut pharmacology

Question 1

List medical conditions in which gastric acid may play a role

Answer 1

Gastrointestinal reflux disease (GERD)
Benign peptic ulcers of the stomach and duodenum
Ulcers secondary to the use of NSAIDs
Ulcers due to the rare Zollinger-Ellison syndrome

Question 2

Describe the mechanism of action of PPIs

Answer 2

Irreversibly bind to H/K ATPase on parietal cells

Question 3

List side effects of PPIs

Answer 3

Nausea
Abdominal pain
Constipation
Flatulence
Decreased absorption of calcium and drugs that require acid
C diff
GI infections
Bronchitis and pneumonia

Question 4

List therapeutic uses of PPIs

Answer 4

Healing of gastric and duodenal ulcers, reduce risk of ulcers and their complications, ameliorate effects of NSAIDs, treatment of gastrinoma

Question 5

What is the mechanism of action of ranitidine?

Answer 5

Histamine H2 receptor blocker
Inhibits acid secretion by reversibly competing with histamine H2 receptors on parietal cells
others: cimetidine, famotidine, nizatidine

Question 6

H2 blockers are more effective at suppressing ______ acid secretion than PPIs

Answer 6

nocturnal

Question 7

List side effects of H2 blockers

Answer 7

Rare
diarrhea
headache
drowsiness, fatigue
muscular pain
constipation

Question 8

Cimetidine can cause _____ in men and ____ in women

Answer 8

gynecomastia, galactorrhea

Question 9

List therapeutic uses of H2 blockers

Answer 9

Dyspepsia, heartburn, uncomplicated GERD, used to tx ulcers

Question 10

What is the mechanism of action of misoprostol?

Answer 10

Prostaglandin analog
Inhibits gastric acid production by binding to the EP3 receptor on parietal cells, has cytoprotective effects by stimulating secretion of mucin and bicarbonate and improves mucosal blood flow

Question 11

What are side effects of misoprostol?

Answer 11

Diarrhea (great for tx of constipation)

Contraindicated in pregnancy, counsel if giving to women of childbearing age

Question 12

Sucralfate binds ____ AND ______

Answer 12

hydrochloric acid and bile salts

Question 13

What is the mechanism of action of sucralfate

Answer 13

Cross links and polymerizes to form a viscous liquid that adheres to ulcer crates and creates a protective barrier
May stimulate local PG and EGF production

Question 14

What are side effects of sucralfate?

Answer 14

Constipation, aluminum poisoning if renal failure, can inhibit absorption of other drugs

Question 15

_____ work fastest and their effects dissipate most quickly

Answer 15

Antacids

Question 16

What is sucralfate?

Answer 16

Octasulfate of sucrose with aluminum hydroxide functional group
Used to treat ulcers

Question 17

What are side effects of antacids?

Answer 17

Altered absorption of other drugs
Alkalosis from NaHCO3
Release of CO2--> belching
Nausea
Abdominal distension

Question 18

Antacids bind ____ and ____

Answer 18

hydrochloric acid and bile salts

Question 19

Omeprazole interferes with the effects of _____ in some patients

Answer 19

clopidegrel

Question 20

Cimetidine interferes with the effects of ____ in some pateints

Answer 20

warfarin

Question 21

_____ in antacids can cause constipation, whereas _____ can cause diarrhea

Answer 21

aluminum= constipation
magnesium= diarrhea

Question 22

What is appropriate therapy for peptic ulcers

Answer 22

acid suppression for 8 weeks

document healing only if gastric ulcer, not duodenal

Question 23

Describe helicobacter plyori treatment

Answer 23

PPI + amoxicillin and clarithromycin (or metronidazole)

PPI, bismuth, tetracycline, metronidazole

Question 24

What is the mechanism of action of metoclopride

Answer 24

Facilitates release of ACh from enteric neurons: Activates 5-HT4 receptors on cholinergic neurons and acts as an antagonist at D2 receptors
Results in increased gastric motility, enhanced transit

Question 25

There is a black box warning on metoclopramide for _________

Answer 25

neurological side effects- Parkinsons like symptoms, tardive dyskinesia

Question 26

Ondansetron is a ______ antagonist that is used as an antiemetic

Answer 26

5-HT3 receptor antagonist

Question 27

Describe the mechanism of action of ondansetron (oterhs are granisetron, dolasetron, alosetron)

Answer 27

5-HT3 receptor blockers, antiemetic properties

highest 5-HT3 receptor concentration in nucleus tractus solitarius of vagus nerve

Question 28

What are adverse reactions to 5-HT3 receptor blockers

Answer 28

constipation, diarrhea, headache, and light-headedness

Question 29

What is the mechanism of action of prochlorperazine

Answer 29

D2 blocker in the chemoreceptor trigger zone, useful in motion sickness
Useful “general purpose” anti-nausea and anti-emetics

Question 30

What is the mechanism of action of promethazine and meclizine

Answer 30

H1 receptor blocker

acts on vestibular afferents within the brainstem, useful for motion sickness and post-operative emesis

Question 31

What is the mechanism of action of scopolamine

Answer 31

Anticholinergic used to treat motion sickness, no role in chemotherapy induced nausea

Question 32

What is the ONLY cause of reversible cyclic vomiting syndrome?

Answer 32

THC

Relieved by hot shower

Question 33

Dronabinol is useful for _______ properties in patients receiving cancer chemotherapy for which other medications are not effective

Answer 33

anti-emetic

Question 34

Scopolamine is a ______ that is ONLY useful for motion sickness

Answer 34

anticholinergic