COPE: Cannabinoids to Obviate Pain Experiment After Knee Replacement

Unity Health Toronto

Status and phase: Unknown; Phase 3; Phase 2

Conditions: Arthroplasty, Replacement, Knee

Treatments: Drug: Cannabinol; Drug: Placebo oral capsule

Study type: Interventional

Funder types: Other

Identifiers

NCT03675971

RCT19-366965

Details and patient eligibility

About

Total knee replacement is a major and painful orthopaedic (joint and bone) surgery where the knee joint is replaced with an artificial joint. It is an effective and successful procedure to treat severe knee arthritis and reduce pain, but many patients report intense pain after the surgery.

Postoperative pain control is predominated by opioids (morphine-based drugs). While opioids are effective to manage the pain, they can have acute and chronic complications, including confusion, nausea, vomiting, constipation and high risk of addiction.

Medical cannabis is an effective and safe alternative for pain treatment. Recent studies showed that patients have reported a reduction in opioid usage when taking cannabis as a substitute for pain relief.

This study aims to investigate whether adding medical cannabis (cannabidiol - CBD) treatment will decrease the amount of opiates needed in the first 2 weeks after knee replacement compared to a group given placebo.

Full description

COPE (Cannabinoids to Obviate Pain Experiment after knee replacement) will be a single-centre, prospective, randomized, placebo-controlled, superiority trial, with two parallel groups designed to investigate the effect of cannabis as postoperative pain treatment compared to placebo on total opioid consumption after total knee replacement.

Eligible patients are: men and non-pregnant women aged ≥18 years scheduled to undergo primary total knee replacement. and with no opioid usage within the last 3 months or history of narcotic abuse.

Patients will be recruited at the department of orthopaedic surgery at St Michael's Hospital (Toronto - Canada), and informed consent will be obtained from those eligible. Central computer-generated randomization will be used to randomly assign participants to cannabis or placebo groups (1:1 ratio). Only the study pharmacist will know allocated treatments.

Enrollment: 220 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• 18 years of age and older
• Men and women
• Patients with radiographic confirmation and clinical correlation for severe osteoarthritis diagnosis with an indication for total knee replacement
• Patients undergoing primary unilateral total knee replacement
• Patient is able to provide informed consent to participation in the study

Exclusion criteria

• Pregnancy
• Breastfeeding
• Current opioid use
• Cognitive impairment or mental illness (e.g., dementia, Alzheimer disease and psychoses), which will prevent patients from reliably providing primary outcome data
• Unable to swallow an oral tablet (medication)
• History of opiate, narcotic and alcohol abuse
• Revision total knee replacement surgery
• High risk of falls as determined by the treating physician
• Patients refusing participation
• Pre-existing/ regular cannabis use

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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220 participants in 2 patient groups, including a placebo group

Medical Cannabis

Experimental group

Description:

Drug: Cannabidiol

Treatment:

Drug: Cannabinol

Placebo

Placebo Comparator group

Description:

Placebo comparator

Treatment:

Drug: Placebo oral capsule