Helicobacter Pylori

Question 1

Helicobacter pylori- is gram negative or gram positive?

Answer 1

Gram negative

Question 2

What conditions is H. Pylori associated with?

Answer 2

• Peptic ulcer disease (95% of duodenal ulcers, 75% of gastric ulcers)
• Gastric cancer
• B cell lymphoma of MALT tissue (eradication of H pylori results causes regression in 80% of patients)
• Atrophic gastritis

Question 3

When would you test for H Pylori?

Answer 3

Dyspepsia and reflux symptoms - use this as your primary strategy before offering PPI.

Question 4

Describe the Urea Breath test.

Answer 4

• Patients consume a drink containing carbon isotope 13 (13C) enriched urea.
• Urea is broken down by H. pylori urease
• After 30 mins patient exhale into a glass tube
• Mass spectrometry analysis calculates the amount of 13C CO2

Question 5

What is the wash out period before doing the urea breath test or for retesting for success regarding antibiotics or PPIs?

Answer 5

• 4 weeks of treatment with an antibacterial
• 2 weeks of an antisecretory drug (e.g. a proton pump inhibitor)

Question 6

What are the 2 tests that are mainly used now to test for H.Pylori?

Answer 6

Urea breath test and Serology (Serum Antibody)

Question 7

When would you not use the serum antibody test?

Answer 7

• Elderly
• Children
• Post-treatment - it remains positive even after eradication. So therefore not useful to assess success of eradication.

Question 8

What is a more specific & sensitive test?

Answer 8

Urea Breath test (Sens ~97%, Spec 98%)

>

Serum Antibody (Sens 85% Spec 80%)

Question 9

What are some other H. Pylori tests that can be done apart from the Urea breath test and the serum antibody test?

Answer 9

• CLO (Rapid urease test)
• Serum antibody
• Gastric biopsy (histological result - most specific & sensitive test)
• Culture of gastric biopsy
• Stool antigen test. (90%, specificity 95%

Question 10

How is the CLO test also known as?

Answer 10

The rapid urease test

Question 11

How is the CLO test done?

Answer 11

A biopsy sample is mixed with urea and a pH indicator.

Question 12

How can you give a patient a home urea breath test?

Answer 12

Prescribe it on an FP10

~£20

Question 13

What is your first line “Triple Therapy “ for eradicating H. Pylori?

Answer 13

• For 7 Days twice daily
• Full dose PPI + amoxicillin 1g + clarithromycin 500mg or metronidazole 400mg
• If penicillin allergic offer PPI + clarithromycin +metronidazole

Question 14

If a patient has had a lot of exposure to clarithromycin, what can you prescribe instead?

(You can use this as your second line strategy)

Answer 14

If previous use of clarithromycin substitute with:

• Keep Metronidazole as your base
• Substitute clarithromycin or amoxicillin with
  
  • Bismuth & Tetracycline
  • Quinolone (levofloxacin)

Question 15

If eradication is unsuccesful after a second line treatment, what should you do?

Answer 15

Refer to gastro.