The placebo group:Normal saline was administered intravenously as a loading dose of 5ml and PCA as a single dose of 1ml

Efficacy and safety of YZJ-4729 tartrate injection for postoperative analgesia in patients undergoing abdominal surgery: a multicenter, randomized, double-blind, dose-search, placebo and positive drug parallel controlled phase II clinical trial

Efficacy and safety of YZJ-4729 tartrate injection for postoperative analgesia after abdominal surgery: a multicenter, randomized, double-blind, placebo and positive drug parallel controlled phase III clinical trial