A Trial of HR18034 for Postoperative Analgesia in Subjects Undergoing Hemorrhoidectomy.

Inclusion criteria

• Able and willing to provide a written informed consent
• Subjects requiring hemorrhoidectomy under subarachnoid anesthesia
• 18 kg/m2 ≤ BMI ≤ 28 kg/m2
• Conform to the ASA Physical Status Classification
• Women of childbearing age have a negative pregnancy test and are not nursing

Exclusion criteria

• Subjects with a history of myocardial infarction or unstable angina pectoris
• Subjects with atrioventricular block or cardiac insufficiency
• Subjects with a history of ischemic stroke or transient ischemic attack
• Subjects with a history of mental illness and a history of cognitive impairment epilepsy
• Subjects with concurrent painful physical condition that may affect postoperative pain assessment
• Subjects with myelopathy or spinal disease
• Subjects with a history of hemorrhoidectomy
• Abnormal values in the laboratory
• Subject with a history of substance abuse and drug abuse
• Subject with refractory hypertension
• History of hypersensitivity or idiosyncratic reactions to amide-type local anesthetics, opioids, or other drugs that may used in study
• History of substance abuse, drug use and/or alcohol abuse
• HBsAg, HCVAb, HIV antibody and syphilis antibody tested positive during screening period;
• Participated in clinical trials of other drugs (received experimental drugs)
• The inestigators determined that other conditions were inappropriate for participation in this clinical trial