Clinical Study on the Effect of Tegileridine on Postoperative Pain in Patients Undergoing Abdominal Surgery.

This randomized, double-blind, placebo-controlled study will evaluate the efficacy and safety of tegileridine fumarate injection for postoperative analgesia in adults experiencing moderate-to-severe pain after abdominal surgery. Participants will be randomized to receive intravenous tegileridine or matching placebo as part of a standardized multimodal analgesia protocol; all patients will have access to rescue opioid analgesia per institutional practice. The primary objective is to determine whether tegileridine improves postoperative pain control during the first 24-48 hours after surgery. Secondary objectives include comparing cumulative opioid consumption, time to first rescue analgesia, patient-reported satisfaction with pain control, recovery milestones (e.g., time to ambulation), and the incidence of adverse events such as nausea, vomiting, sedation, respiratory depression, pruritus, and constipation. Safety will be monitored throughout the study with predefined stopping and reporting procedures. The results aim to inform whether tegileridine can provide effective and well-tolerated analgesia for patients with moderate-to-severe postoperative pain following abdominal procedures.