Postoperative pain is common, and the pain intensity can be moderate to severe depending on the site of surgery during the first few days after surgery, and an estimated 15% to 45% experience chronic postsurgical pain. When poorly controlled, the pain can have a significant effect on patient recovery. Proper management of postoperative pain is needed to relieve suffering and lead to earlier mobilization, shortened hospital stay, reduced hospital costs, and increased patient satisfaction. The currently proposed clinical use of Dinalbuphine Sebacate is to administer a single dose of NALDEBAIN® intramuscularly approximately 12 to 24 hours prior to the planned surgery for pain relief. Several clinical studies of NALDEBAIN® have been published, such as the use in laparotomy and laparoscopic cholecystectomy. However, toward the arthroscopic shoulder surgery, no article or report has been available publicly yet. The primary objective of this study is to determine the safety and efficacy of single doses of intramuscular NALDEBAIN® on patients scheduled to undergo arthroscopic shoulder surgery.

This is a randomized, double-blind, placebo controlled study. Patients scheduled to undergo arthroscopic shoulder surgery will be invited to participate in this study. After obtaining the written informed consent, each subject should be sequentially assigned an individual screening number instead of his/her name, chart number or identification. Subjects will be randomized to two groups, DS group and Control group. Both groups should be treated with both routine analgesic regimen and a dose of investigational product. Random numbers and assignment treatment were generated by computer program before this study initiated. Statistical analyses should be performed on the data to compare the two groups. Numerical variables will be present with mean and standard deviation and categorical variables will be present with number and percentage.

Inclusion Criteria:

1. Scheduled to undergo arthroscopic shoulder surgery.
2. American Society of Anesthesiology Physical Class 1-3.
3. Ability and willingness to provide informed consent.

Exclusion Criteria:

1. Not willing to adhere to the study visit schedule.
2. With a history of hypersensitivity or allergy to opioids, NSAIDs or sesame oil.
3. With a medical history that may predispose them to abnormal intracranial pressure.
4. Any history of narcotic dependency, addiction, or withdrawal.
5. Any clinically significant condition that may interfere with study assessments.
6. Pregnant or breastfeeding.
7. Nonregular sinus cardiac rhythm or implanted pacemakers.
8. Prescribed antimuscarinic agents, α2-adrenergic agonists, β1-adrenergic antagonists, or antiarrhythmic agents.