Helicobacter pylori infection

Red Flags

H. pylori with active or recent peptic ulcer bleeding — admit; PPI infusion plus eradication once stabilised^[1]
Gastric MALT lymphoma diagnosis — eradicate H. pylori; many regress without chemotherapy^[1]
Family history of gastric cancer plus H. pylori — eradicate; surveillance endoscopy if dysplasia/atrophy^[1]
Persistent H. pylori after first-line eradication — high resistance burden; switch class, do not repeat clarithromycin^[1]

Test-of-cure mandatory^[1]
All treated patients should be tested 4–8 weeks after completing therapy; cure rates with quadruple therapy 80–90%
PPI maintenance after ulcer healing^[1]
Continue PPI for 4–8 weeks after eradication if peptic ulcer; longer if NSAIDs continue

Drug	Class	Adult	Paediatric	Notes
Bismuth quadruple therapy (BQT)^[1]	PPI + bismuth + tetracycline + metronidazole	PPI BD + bismuth subcitrate 120 mg QID + tetracycline 500 mg QID + metronidazole 500 mg QID — 14 days	—	First-line per ACG 2024 in regions of high clarithromycin resistance (>15%); India falls in this category
Concomitant non-bismuth quadruple therapy^[1]	PPI + amoxicillin + clarithromycin + metronidazole	PPI BD + amoxicillin 1 g BD + clarithromycin 500 mg BD + metronidazole 500 mg BD — 14 days	Per weight per ESPGHAN paediatric guideline	Alternative first-line; only use where clarithromycin resistance <15%
Vonoprazan-based dual therapy^[1]	Potassium-competitive acid blocker + amoxicillin	Vonoprazan 20 mg BD + amoxicillin 1 g TID — 14 days	—	Newer first-line option per VOQUEZNA-CAB; superior acid suppression than PPI; emerging data for clarithromycin-resistant strains
Levofloxacin triple (salvage)^[1]	Salvage regimen	PPI BD + amoxicillin 1 g BD + levofloxacin 500 mg daily — 10–14 days	—	Second-line salvage when initial therapy fails; do NOT use clarithromycin in retreatment
Rifabutin-containing rescue regimen^[1]	Rescue therapy	PPI BD + amoxicillin 1 g BD + rifabutin 150 mg BD — 14 days	—	Refractory H. pylori after multiple eradication failures; specialist

Bismuth quadruple therapy (BQT)^[1]

PPI + bismuth + tetracycline + metronidazole

Adult: PPI BD + bismuth subcitrate 120 mg QID + tetracycline 500 mg QID + metronidazole 500 mg QID — 14 days
Paediatric: —

First-line per ACG 2024 in regions of high clarithromycin resistance (>15%); India falls in this category

Concomitant non-bismuth quadruple therapy^[1]

PPI + amoxicillin + clarithromycin + metronidazole

Adult: PPI BD + amoxicillin 1 g BD + clarithromycin 500 mg BD + metronidazole 500 mg BD — 14 days
Paediatric: Per weight per ESPGHAN paediatric guideline

Alternative first-line; only use where clarithromycin resistance <15%

Vonoprazan-based dual therapy^[1]

Potassium-competitive acid blocker + amoxicillin

Newer first-line option per VOQUEZNA-CAB; superior acid suppression than PPI; emerging data for clarithromycin-resistant strains

Levofloxacin triple (salvage)^[1]

Salvage regimen

Second-line salvage when initial therapy fails; do NOT use clarithromycin in retreatment

Rifabutin-containing rescue regimen^[1]

Rescue therapy

Refractory H. pylori after multiple eradication failures; specialist

Take all four medications together for the full 10–14 days even when symptoms improve early; incomplete therapy drives resistance^[1]
Bismuth turns stools black — this is normal; metallic taste is common with metronidazole^[1]
Avoid alcohol with metronidazole or tinidazole (disulfiram-like reaction)^[1]

Active peptic ulcer bleeding with H. pyloriHospital admission; gastroenterology for endoscopic haemostasis^[1]
Gastric MALT lymphomaGastroenterology and haematology / oncology^[1]
Multiple eradication failuresGastroenterology for culture-and-sensitivity and rescue regimen^[1]
H. pylori with gastric atrophy or intestinal metaplasiaGastroenterology for endoscopic surveillance^[1]

Diagnosis and eradication of H. pylori — non-bismuth quadruple or bismuth quadruple regimens reflecting rising clarithromycin resistance.

1.ACG Clinical Guideline: Treatment of Helicobacter pylori Infection (2024 update); Maastricht VI / Florence Consensus 2022 (2024)