Funding not obtained

This study is designed to investigate the effect of dronabinol on post operative pain in patients undergoing total knee replacement (for their own clinical care).

Total knee replacement is a common surgical procedure that restores function to the damaged joint. Recovery from this procedure takes weeks and requires opioids to manage post-surgical pain. The goal of this study is to investigate whether dronabinol (synthetic THC) can reduce pain and the need for opioid medication following this particular surgery.

Subjects will be recruited from the Department of Orthopedic Surgery. All subjects will undergo total knee replacement as part of their clinical care (the surgery itself is not part of this study). The study begins following discharge from the hospital. They will be asked to take dronabinol or placebo as they recover from surgery. During this time they will be given their usual pain medications at discharge which includes opioids for pain. The opioids are to be taken if the subject is experiencing pain. The investigator's hypothesis is that subjects taking dronabinol will need fewer doses of opioids to control pain.

Inclusion Criteria:

• Participants undergoing total knee arthroplasty (TKA) at the CUIMC department of orthopedic surgery as part of their clinical care.
• Able to give informed consent and comply with study procedures in English

Exclusion Criteria:

• Meet DSM-V criteria for current major psychiatric illness, such as bipolar disorder, major depression, or psychosis. Subjects with a current substance use disorder will be excluded. Subjects with a past cannabis use disorder are excluded.
• Diagnosis of a major medical or neurological disorder, including orthostatic hypertension, cardiovascular disease (congestive heart failure, unstable angina, or a history of cardiac infarction), hypotension, or neurodegenerative disorders.
• Subjects taking medications that can lead to a drug interaction.