The aim of this project is to determine whether an NZ-produced Cannabis-Based Medication (CBM) is a safe and effective long-term treatment for insomnia in patients with chronic back pain.
Significance
There is increasing interest in the use of CBM by patients with chronic pain. There is anecdotal evidence of benefit but little evidence from clinical trials. The research on a link between CBM and sleep is currently very limited. Few investigators have studied this question as a primary study objective, and those reporting effects of CBM on sleep as a secondary outcome have typically been of short duration and have often used inconsistently reported and unvalidated outcome measures. We could find no long-term trials that have examined this question in a rigorous manner.
Objective
The primary goal of our trial is to determine if there is a therapeutic role for CBMs in improving sleep in patients with chronic pain.
Methods
The study will be a randomised, double-blind, placebo-controlled crossover study on the efficacy of CBM in treating insomnia in patients with chronic back pain. The study will be run in the Bay of Plenty, where the CI is a Specialist Pain Medicine Physician. The administering Institution will be the University of Auckland, where the CI is an MD (Doctor of Medicine) candidate in the Department of Anaesthesiology.
Participants
Men & women aged between 25 and 85 with a history of chronic back pain (neck, thoracic or lumbar) and a diagnosis of Insomnia on the Insomnia Severity Index (ISI) scale.
Investigational Medicinal product (IMP): Cannasouth evalaCann: ( D9- tetrahydrocannabinol (THC) 10mg per ml and Cannabidiol (CBD) 15mg per ml), an oil based natural extract, administered orally. This product has been verified by the NZ Medicinal Cannabis Agency as meeting the minimum quality standards. It can thus be prescribed and dispensed as any prescription medication. Cannasouth will also provide placebo medication, consisting of just the carrier oil.
Trial Procedure
We will obtain ethics committee approval and informed consent from all patients. Following randomisation, baseline measurements will be taken. Participants will be provided an actigraphic device to monitor sleep for the duration of the study. After a 14-day baseline period, each participant will collect the IMP (CBD or placebo) from the trial pharmacist. Participants will be asked to take the IMP one hour before sleep. Subjects will be asked to start at 0.2ml and titrate up by 0.2ml per day to a maximum dose of 1 to 1.5 ml per night, with the aim of balancing positive effect of sleep against any adverse effects. Participants will be regularly monitored throughout the study for dosage, pain, and sleep (via text messages), and will have research clinic visits at approximately 28-day intervals for safety checks and questionnaire completion. At approximately 84 days (i.e., 12 weeks), participants will enter a 14-day wash out period. Participants will then begin second arm of study using the IMP that they did not receive in first arm (CBM/Placebo), but with otherwise identical research procedures.
Outcome Measures
The primary outcome measure will be the total score of the ISI. A reduction in the ISI score of six points or greater would be considered a clinically significant difference, and the study has been sized on this basis. Secondary outcome measures will include the the Brief Pain Inventory (BPI) and sleep parameters from the actigraphic device.
Likely Benefits
Our results will inform the future use of CBM for insomnia in patients with chronic pain. Given the extent of the problem of sleep disturbance in patients with chronic pain, the potential clinical value of this is substantial.
Dr Saad Anis
University of Auckland & Hauora A Toi Bay of Plenty, New Zealand
The project was awarded A$19,664 funding through the ANZCA research grants program for 2024.