A 52-year-old man with a 3-year history of epigastric pain presents with hematemesis and melena. Upper endoscopy reveals a 2 cm ulcer in the antrum with active bleeding. H. pylori serology is positive. After successful endoscopic hemostasis, what is the drug of choice for eradication therapy?

Explanation

## H. pylori Eradication Regimen **Key Point:** Triple therapy (PPI + two antibiotics) is the gold standard for H. pylori eradication in peptic ulcer disease, particularly in bleeding ulcers. ### Standard Triple Therapy Components | Component | Drug | Dose | Duration | |-----------|------|------|----------| | **PPI** | Omeprazole | 20 mg BD | 7–14 days | | **Antibiotic 1** | Amoxicillin | 1 g BD | 7–14 days | | **Antibiotic 2** | Clarithromycin | 500 mg BD | 7–14 days | **High-Yield:** This regimen achieves >90% eradication rates when compliance is good. It is the first-line recommendation in most international guidelines (NICE, ACG, European) for H. pylori-positive peptic ulcer disease. ### Why Triple Therapy? 1. **Monotherapy failure:** PPI alone does not eradicate H. pylori; it only suppresses symptoms. 2. **Dual therapy inadequate:** Two-drug regimens have lower eradication rates (~70–80%) and higher resistance emergence. 3. **Synergistic effect:** The combination of acid suppression (PPI) + two antibiotics with different mechanisms achieves bacterial kill and prevents resistance. **Clinical Pearl:** In H. pylori-positive bleeding peptic ulcers, eradication therapy is essential to prevent recurrent bleeding (reduces rebleeding risk from ~30% to <5%). **Mnemonic:** **OAC** = Omeprazole + Amoxicillin + Clarithromycin (the classic triple therapy). ### Alternative Regimens (if clarithromycin resistance suspected) - **Quadruple therapy:** PPI + bismuth + tetracycline + metronidazole (if resistance >15–20%) - **Sequential therapy:** PPI + amoxicillin × 5 days, then PPI + clarithromycin + metronidazole × 5 days (emerging option in high-resistance regions) [cite:Harrison 21e Ch 297]