Proton pump inhibitors

Question 1

1) Name 3 PPIs.

Answer 1

1) Lansoprazole, Omeprazole, Pantoprazole.

Question 2

Give the 3 main clinical indications for use of PPIs, in which PPIs are first line treatments.

Answer 2

1) Prevention and treatment of peptic ulcer disease, including NSAID-associated ulcers.
2) Symptomatic relief of dyspepsia and GORD.
3) Eradication of H. Pylori infection on which they are used in combination with antibiotic therapy.

Question 3

Describe the mechanism of action of PPIs.

Answer 3

Irreversibly inhibit H+/K+ ATPase in gastric parietal cells which is responsible for secreting H+ and producing gastric acid.

Question 4

1) Give 2 common side effects of PPIs.
2) Give a more severe side effect of PPIs which might occur with prolonged treatment.
2a) How should you monitor for this side effect?
3) What infection might result from PPIs potentially reducing the body’s host defence against infection?
4) PPIs can increase the risk of what when taken at high doses for prolonged periods of time?

Answer 4

1) GI disturbances and headaches.
2) Hypomagnesaemia (can lead to tetany and ventricular arrhythmia).
2a) If on prolonged treatment (>1 year), check serum Magnesium levels.
3) C. Diff.
4) Fractures (identify and treat patients at risk of osteoporosis).

Question 5

1) Symptoms of what disease should be enquired about before and during patient treatment with PPIs and H2 antagonists?
2) Why is this?

Answer 5

1) Gastric cancer.

2) Because these 2 drugs can mask the symptoms of gastric cancer.

Question 6

Why are lansoprazole and pantoprazole preferred over omeprazole if the patient is taking clopidogrel?

Answer 6

Because omeprazole may reduce the anti platelet effect of clopidogrel by decreasing its activation by cytochrome P450 enzymes

Question 7

Why should patients undergoing investigation for H. Pylori infection withhold their PPI for 2 weeks before testing?

Answer 7

Because it increases the chance of a false negative result,