Antihistamines - H2 receptor blocker (for acid-peptic disease)

Question 1

H2 receptors are involved in the production of gastric acid. Which cells can histamine bind with an induce the secretion of gastric acid?

1 - goblet cells
2 - chief cells
3 - parietal cells
4 - enterochromaffin cells

Answer 1

3 - parietal cells

Question 2

Which of the following is NOT a core H2 receptor antagonist?

1 - Cyclazine
2 - Famotidine
3 - Nizatidine
4 - Ranitidine

Answer 2

1 - Cyclazine

• all end in TIDINE

Question 3

Famotidine, Nizatidine and Ranitidine are all H2 receptor antagonists. Which 2 of the following re these medications indicated in?

1 - anaphylaxis
2 - peptic ulcers
3 - gastro-oesophageal reflux disease
4 - ileus

Answer 3

2 - peptic ulcers
3 - gastro-oesophageal reflux disease

• PPI is 1st line, but these drugs can be used alongside PPIs or when PPIs are contraindicated

Question 4

What type of receptor are H2 receptors?

1 - nuclear receptors
3 - ion channel receptors
3 - GPCRs
4 - enzyme-linked receptors
5 - ligand gates receptors

Answer 4

3 - GPCRs
- irreversible bind with H2 receptors

Question 5

Although the H2 receptor antagonists Famotidine, Nizatidine and Ranitidine are all safe drugs, they can cause some mild side effects. Which of the following is NOT one of these?

1 - diarrhoea and/or constipation
2 - headaches
3 - hepatic encephalopathy
4 - dizziness

Answer 5

3 - hepatic encephalopathy

Question 6

Although the H2 receptor antagonists Famotidine, Nizatidine and Ranitidine are all safe drugs, they should be titrated in which of the following?

1 - older patients >75 y/o
2 - renal impairment
3 - liver disease
4 - chronic heart failure

Answer 6

2 - renal impairment
- these drugs are excreted by the kidneys

Question 7

How are all the H2 receptor antagonists Famotidine, Nizatidine and Ranitidine typically administered?

1 - IV
2 - orally
3 - SC
4 - rectally

Answer 7

2 - orally

• Famotidine = 20-40mg/12h
• Nizatidine
• Ranitidine = 150mg/12h

Question 8

When prescribing H2 receptor antagonists Famotidine, Nizatidine and Ranitidine, if there are symptoms of dyspepsia, GORD or peptic ulcer disease, what should patients be screened for?

1 - oesophageal cancer
2- gastric cancer
3 - helicobacteria pylori
4 - hiatus hernia

Answer 8

3 - helicobacteria pylori