amoxicillin + tetracycline + bismuth + esomeprazole

This is a four-drug combination therapy consisting of amoxicillin, tetracycline, bismuth (typically as bismuth subcitrate or subsalicylate), and esomeprazole. It is used primarily for the eradication of Helicobacter pylori infection, especially in cases where resistance to other antibiotics (such as clarithromycin or metronidazole) is prevalent. The regimen combines two antibiotics with different mechanisms (amoxicillin and tetracycline), a bismuth salt that has antimicrobial and mucosal protective effects, and a proton pump inhibitor (esomeprazole) to suppress gastric acid secretion. This combination aims to maximize eradication rates by targeting H. pylori through multiple pathways while reducing the risk of antibiotic resistance[5][6]. Esomeprazole enhances antibiotic efficacy by increasing gastric pH.