Helicobacter pylori

Doses are oral and for adults unless otherwise stated. Visit the Health Products Regulatory Board website or the printed Irish Medicines Formulary for drug SPCs, dosage, contraindications, interactions, or IMF/BNF/BNFC/MIMS. See guidance on dosing in children for quick reference dosage/weight guide.

Letters indicate strength of evidence range from A+ (systematic review) to D (informal opinion). Statins can interact with some antibiotics and increase the risk of rhabdomyolysis. Amiodarone and drugs which prolong the QT interval can interact with many antibiotics. Many antibiotics increase the risk of bleeding with anticoagulants. Please refer to our Drug Interactions Table for further information.

Eradication of Helicobacter pylori

  • Eradication is beneficial in duodenal ulcer, gastric ulcer and low grade MALTOMA, but NOT in GORD.A In non-ulcer dysepsia, 8% of patients benefit.
  • Triple treatment attains >85% eradication.A+
  • Do not use clarithromycin or metronidazole if used in the past year for any infection.A+

Managing Symptomatic Relapse

  • Duodenal ulcer/Gastric ulcer: Retest for helicobacter if symptomatic
  • Non-ulcer dyspepsia: Do not retest, treat as functional dyspepsia.
  • In treatment failure consider endoscopy for culture & susceptibility.C Use 14 days BD PPI plus 2 antibiotics. Consider adding bismuth salt.


Treatment Adult Dose TX Duration
First LineA+ PPI
PLUS clarithromycin
AND metronidazole
250 mg BD  
400mg BD
All for 7 daysA

14 days in relapse or maltoma
PLUS clarithromycin AND amoxicillin
500 mg BD
1g BD
Alternative RegimensA+ PPI OR
ranitidine bismuth citrate
400 mg BD
PLUS 2 antibiotics:
amoxicillin 1 g BD
clarithromycin A+ 500 mg BD
metronidazole 400 mg B

See guidance on dosing in children for quick reference dosage/weight guide.

Patient Information

We recommend patients use the website developed by HSE/ICGP/IPU partnership www.undertheweather.ie for tips on how to get better from common infections without using antibiotics, what you can do for yourself or a loved one and when to seek help.

Reviewed June 2016

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