A Study 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 ≤ 30 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
• Spinal or spinal lesions that were determined by the investigator to be unable to tolerate subarachnoid anesthesia
• Subjects with a history of hemorrhoidectomy
• Subjects with a history of constipation
• Subjects with a history of perianal disease
• Abnormal values in the laboratory
• Subject with heart rate <50 or >100 beats per minute.
• 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 prohibited drug use
• Participants who may be affected by alcohol, or drug abstinence during the study 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