Study Evaluating the Safety, Efficacy and Pharmacokinetics of SYH9089 Injection in Patients Undergoing Abdominal Surgery.

Who cannot join

• 1. Patients with a history of hypersensitivity to the investigational drug, comparator drug, surgical anesthetics, rescue analgesic drugs, or other drugs that may be used during the trial; 2. Patients with a history of drug abuse/substance use, or those with positive results on a drug abuse screening; 3. Patients with neurological/psychiatric, respiratory, endocrine, hematologic, musculoskeletal, gastrointestinal, cardiovascular systems, or hepatic/renal diseases, judged by the investigator to be unsuitable for the trial; 4. Patients with a history of diabetes mellitus; 5. Patients with a history of myocardial infarction or unstable angina within 1 year prior to randomization; 6. Patients scheduled to undergo purely diagnostic exploratory surgery or palliative tumor resection, judged by the investigator to be unsuitable for the trial; 7. Patients with advanced malignant tumors, judged by the investigator to be unsuitable for the trial; 8. Combined with other pain conditions that may confound the evaluation of postoperative pain according to the investigator; 9. Patients with a history of severe or refractory postoperative nausea or vomiting; 10. Patients scheduled to receive interventions (e.g., intraperitoneal hyperthermic chemotherapy, local/intraperitoneal chemoperfusion, or infrared therapy) during the observation period (randomization to 120h after administration) that may interfere with postoperative pain assessment 11. Use of the following drugs for less than 5 half-lives before randomization (based on the actual drug instructions; or within 7 days prior to randomization if the half-life is unclear) which, in the investigator's judgement, may affect the evaluation of analgesic efficacy. These include, but are not limited to: narcotics (opioids), local anesthetics, non-steroidal anti-inflammatory drugs (NSAIDs), sedative-hypnotics, non-benzodiazepines, sedative anesthetics, glucocorticoids (except for topical use), antiepileptics, anxiolytics, antidepressants, as well as Chinese herbal medicines or proprietary Chinese medicines with sedative or analgesic effects; 12. Use of strong CYP1A2 inhibitors for less than 5 half-lives before randomization (e.g., atazanavir, ciprofloxacin, enoxacin, fluvoxamine, ethinylestradiol) ； 13. Subjects with abnormal findings during the screening period (prior to admission) in vital signs, physical examination, 12-lead ECG, or laboratory tests, which in the investigator's judgement make the subject unsuitable for participation in this trial, including:
• Patientss with poorly controlled blood pressure despite medication: systolic blood pressure ≥160 mmHg and/or diastolic blood pressure ≥100 mmHg; or systolic blood pressure <90 mmHg;
• 12-lead ECG: QTcF ≥450 ms for males or ≥470 ms for females, or a history of severe arrhythmias such as second-degree type II or higher atrioventricular block, or a history of cardiac insufficiency;
• Coagulation function: PT > ULN + 3 seconds and/or APTT > ULN + 10 seconds;
• Liver function: ALT and/or AST ≥ 2 × ULN; TBIL ≥ 1.5 × ULN; ALB < 30 g/L;
• Renal function: Cr ≥ 1.5 × ULN;