A patient has a gastric ulcer, and a culture of the secretions reveals Helicobacter pylori. Which medication should the nurse administer along with omeprazole (Prilosec)?

Helicobacter pylori is a gram-negative bacterium responsible for the majority of peptic and gastric ulcers. Standard eradication therapy combines a proton pump inhibitor (PPI) such as omeprazole with antibiotic regimens. The most widely recommended first-line triple therapy pairs omeprazole with two antibiotics — typically amoxicillin and clarithromycin — or with metronidazole and clarithromycin when the patient is penicillin-allergic. Amoxicillin, a broad-spectrum aminopenicillin, is active against H. pylori and is a core component of these regimens because it disrupts bacterial cell-wall synthesis, reducing the bacterial load that the PPI can then help clear by raising gastric pH. Ceftriaxone is a third-generation cephalosporin used primarily for serious systemic infections and is not part of H. pylori eradication regimens. Cotrimoxazole (trimethoprim-sulfamethoxazole) is not a recommended H. pylori treatment. Erythromycin is not used in standard H. pylori eradication protocols, though clarithromycin (a related macrolide) is. Students sometimes confuse erythromycin with clarithromycin; only clarithromycin has an established role in H. pylori therapy, making amoxicillin the best answer here when paired with omeprazole.