Dronabinol and Epidiolex to Manage Uncontrolled Residual Symptoms of Buprenorphine Initiation Trial

Dronabinol and Epidiolex to Manage Uncontrolled Residual Symptoms of Buprenorphine Initiation Trial

The goal of this pilot study is to test novel, adjunctive pharmacotherapy for patients with opioid use disorder (POUD) who may be at risk for overdose and other poor opioid use disorder (OUD) outcomes even after initiating buprenorphine. The investigator team proposes to test the effectiveness of combined dronabinol (synthetic delta-9-tetrahydrocannabinol [THC]) and Epidiolex (cannabidiol [CBD]) - two FDA-approved cannabinoids - to improve retention in buprenorphine treatment and reduce opioid use among POUD who are early in treatment. POUD who are early in treatment are at a critical juncture-a moment of opportunity and motivation, but also of high risk of return to opioid use and loss to follow up.

OUD and opioid overdose death rates remain shockingly high in the United States fueled by high potency opioids like fentanyl. Buprenorphine is an evidence-based therapy for OUD that reduces mortality, improves OUD outcomes, and is increasingly available. Three-month buprenorphine retention halves all-cause mortality; however, only 40-60% of POUD are retained in buprenorphine treatment for 3 or more months. Further, POUD who use fentanyl report protracted opioid withdrawal symptoms including anxiety, pain, insomnia, and opioid cravings, even months after reaching maximum doses of buprenorphine. Nearly 50% of POUD who use fentanyl return to use within 3 months.12 To improve success of buprenorphine treatment, new strategies for starting buprenorphine have emerged, such as low-dose initiation with ongoing opioid agonists, however, few interventions exist to improve treatment after starting buprenorphine, and those that exist are non-pharmacologic. Alpha-2-agonists (e.g., clonidine) reduce some withdrawal symptoms but can only be given for a short time without cardiac side effects. Pharmacologic adjuncts to buprenorphine are desperately needed to improve OUD outcomes in the fentanyl era.

Cannabis, the two key ingredients of which are THC and CBD, reduces opioid withdrawal in observational studies and thus has biologic plausibility for improving buprenorphine treatment retention. In two randomized trials, THC improved acute opioid withdrawal symptoms (e.g., muscle aches, muscle tension, and flu-like prodrome) a common driver of ongoing opioid use. THC is also effective in reducing acute and chronic pain in POUD another driver of ongoing use; however, patients receiving THC alone may experience adverse effects, such as panic, anxiety, and poor cognition. Co-administration with CBD may counteract these effects and maximize THC's benefits. In pre-clinical and clinical trials CBD reduces anxiety, pain, cue-induced opioid cravings, and attentional bias to drug-induced cues. When THC and CBD are co-administered, patients experience improved analgesic effects and reduced adverse effects. The overarching hypothesis of this study is that adjunctive dronabinol + Epidiolex improves buprenorphine retention and opioid use in POUD through reducing opioid withdrawal (including cravings, and pain).

The investigator team has developed an innovative 12-week pilot randomized trial of dronabinol + Epidiolex (versus placebo) as an adjunct to buprenorphine for OUD outcomes. 40 POUD participants within 21 days of buprenorphine initiation who are continuing either to use illicit opioids or to experience opioid withdrawal symptoms will be enrolled. Participants will be randomized to one of two arms as described in this registration. Study visits will occur at enrollment, and weeks 1, 2, 4, 8, and 12.

There are two overarching Aims in this study.

Aim 1: To determine the effectiveness and safety of 8- weeks of dronabinol + Epidiolex (vs. placebo) as an adjunct to buprenorphine in improving retention in OUD treatment and reducing opioid use. Hypothesis 1a: The dronabinol + Epidiolex (vs. placebo) group will have better 12-week retention in OUD treatment. Hypothesis 1b: The dronabinol + Epidiolex (vs. placebo) group will report less illicit opioid use. Hypothesis 2: The dronabinol + Epidiolex (vs. placebo) group will have no difference in significant adverse events or treatment limiting adverse events.

Aim 2: To explore the mechanism by which cannabinoids may improve OUD outcomes after buprenorphine initiation in POUD. The investigator team will explore how dronabinol + Epidiolex use are associated with change in opioid withdrawal symptoms, opioid cravings, and pain and whether these changes are associated with OUD outcomes. Hypothesis 3: The dronabinol + Epidiolex (vs. placebo) group will have fewer withdrawal symptoms, opioid cravings and pain, which will mediate the impact of cannabinoids on OUD outcomes.

Inclusion Criteria:

• Fluency in English and Spanish
• The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnosis of OUD
• Newly initiated on buprenorphine within 21 days
• Positive urine toxicology for opioids other than buprenorphine in the past week OR opioid withdrawal symptoms in the past week based on the Clinical Opioid Withdrawal Scale (COWS) >=5
• Any cannabis use in the past at or after the age of 18 years based on self-report

Exclusion Criteria:

• Urine toxicology positive for cannabinoids
• Inability to provide informed consent
• Liver tests (AST or ALT) >3 times the upper limit of normal, or a history of liver disease
• Pregnancy or breast/chest feeding
• Unstable cardiac disease, history of hypotension or syncope
• Psychotic disorder, or history of suicidal behavior and/or ideation
• Progressive neurological conditions, frequent falls, or history of epileptic seizures
• Severe alcohol use disorder, benzodiazepine use disorder or stimulant use disorder
• Other serious medical conditions that would be a contraindication to THC or CBD use