A 52-year-old woman with rheumatoid arthritis has been taking naproxen 500 mg twice daily for 8 months with good disease control. She now presents with epigastric pain, nausea, and dark stools for 2 days. Her hemoglobin has dropped from 12.5 g/dL to 10.2 g/dL. Upper endoscopy reveals a 1.5 cm gastric ulcer with active bleeding (Forrest IIb). The ulcer is successfully treated with endoscopic hemostasis. What is the most appropriate next step in management?