Evigrade
Minor

Amoxicillin × Metronidazole

Penicillins with extended spectrum×Imidazole derivatives (antiprotozoal / antibacterial)

Mechanism

Target combination in triple and quadruple Helicobacter pylori eradication (Maastricht VI/Florence Consensus 2022, Kyoto Global Consensus). Synergistic antibacterial action.

Symptoms

Possible combination side effects: metallic taste (from metronidazole), nausea, diarrhoea. In some patients, disulfiram-like reaction with alcohol on metronidazole.

Management

Standard combination in H. pylori eradication (amoxicillin 1000 mg twice daily + metronidazole 500 mg three times daily + PPI or bismuth for 10–14 days). Exclude alcohol throughout the course and for 48 hours after metronidazole. If metronidazole is intolerated, alternatives: tetracycline or levofloxacin.

Sources

All interactions

Amoxicillin and Metronidazole: interaction, management, sources – Evigrade