Efficacy and Safety Study of Aprepitant Injection for Prevention of Post-operative Nausea and Vomiting

Inclusion Criteria: * aged 18 to 70 years, with a body mass index (BMI) of 18-30 kg/m² and body weight≥45kg. * laparoscopic gynecologic or abdominal surgery under general anesthesia (duration≥1 hour and postoperative hospitalization ≥24 hours), with anesthesia maintained using sevoflurane and remifentanil (propofol maintenance was prohibited); * had≥2 risk factors of PONV; expected to use postoperative opioid within 24 hours after surgery; * American Society of Anesthesiologists (ASA) physical status class I-III. Exclusion Criteria: * planned intrathoracic, transplant, or central nervous system surgeries; * diagnostic-only procedures; * use of local/regional anesthesia (e.g., neuraxial/nerve blocks); * postoperative intensive care unit (ICU) transfer; * preoperative nasogastric/orogastric tube placement (from screening through 24 hours postoperatively) * nausea, vomiting, retching, or organic disease-related emesis (e.g., intestinal obstruction) within 24 hours preoperatively; history of malignancy, epilepsy, or vestibular dysfunction; * hypersensitivity to aprepitant; * recent use of aprepitant/NK1 antagonists (within 2 weeks prior to randomization), antiemetics (including 5-HT3 antagonists, corticosteroids; within 1 week), strong CYP3A4 inhibitors/substrates (within 1 week), CYP3A4 inducers (within 4 weeks), or warfarin (within 2 weeks); * clinically significant laboratory abnormalities (ALT/AST ≥2×upper limit of normal \[ULN\], total bilirubin ≥1.5×ULN, creatinine ≥1.5×…