Efficacy of a Therapeutic Combination of Dronabinol and PEA for Tourette Syndrome

Study Overview
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Brief Summary
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This is an investigator-initiated proof of concept study with the purpose to examine the safety, tolerability and feasibility of Dronabinol (synthetic Δ9-THC) and PEA for the treatment of adults with Tourette syndrome.

Detailed Description
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The investigators propose a 12-week, investigator-initiated, open-label trial of a therapeutic combination of Dronabinol and PEA in 18 adults with Tourette syndrome. Participants will receive Dronabinol and PEA in combination for the duration of the trial. The goal for this pilot study is to (1) provide initial safety, feasibility and tolerability data on both Dronabinol and PEA in a TS population and (2) provide data in order to make a more informed decision regarding the appropriate sample size and design of a larger clinical trial to prove efficacy (i.e. sample size and trial duration in large efficacy trial of the Dronabinol/PEA combination in TS).

Official Title
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Examining the Efficacy of a Therapeutic Combination of Dronabinol (Synthetic Δ9-tetrahydracannabinol) and Palmitoylethanolamide for Tourette Syndrome

Conditions
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Tourette Syndrome

Intervention / Treatment
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* Drug: Dronabinol and Palmitoylethanolamide


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult between 18-60 years of age Meet DSM-5 criteria for the diagnosis of Tourette syndrome Significant current tic symptoms: YGTSS total tic score greater than or equal to 22 at baseline On stable psychiatric medication regimen for a minimum of 4 weeks prior to beginning the trial Accepted method of birth control Exclusion Criteria: Comorbid bipolar disorder, psychotic disorder, substance use disorder, developmental disorder or intellectual disability (IQ<70) Recent change (less than 4 weeks) in other medications that have potential effects on tic severity (such as alpha-2 agonists (guanfacine, clonidine or prazosin), SSRIs, clomipramine, naltrexone, lithium, anxiolytics, topiramate, baclofen etc.). Medication change is defined to include dose changes or medication discontinuation. Recent change in behavioral treatment for Tourette syndrome or comorbid conditions (i.e. OCD) within the last 4 weeks or initiation of behavioral therapy for tics within the last 12 weeks. Taking any co-medications (over the counter or prescription), food supplements/additives which can have a drug interaction with dronabinol or PEA. Positive pregnancy test or drug screening test History of cannabis dependence Significant Medical Comorbidity History of hypersensitivity to any cannabinoid or sesame oil

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Interventional Model Description: Participants will receive two active medications and will be followed-up bi-weekly for 12 weeks.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dronabinol and Palmitoylethanolamide<br>All participants will be titrated up on Dronabinol dose during the first week of the trial (2.5mg Dronabinol for 3 days and then 5mg Dronabinol for 4 days increasing to 10mg Dronabinol for the remainder of the trial). Dronabinol will only be increased to 10mg at the week 1 assessment if the subject is tolerating the 5mg dose of Dronabinol and the Dronabinol may be reduced based on patient side-effects. All participants will receive two 400mg tablets of PEA daily for the same 12 weeks that they receive the Dronabinol. | Drug: Dronabinol and Palmitoylethanolamide<br>* Participants will receive Dronabinol which will be slowly titrated in the first week of the study. They will be followed for a total of 12 weeks; in addition, participants will receive the PEA in a standing dose of 400mg. They will be followed for a total of 12 weeks.<br>* Other names: Normast;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Tic Severity | Yale Global Tic Severity Scale (YGTSS) (Total Tic Score) The YGTSS tool gives ratings in 5 domains: Total Motor Tic Score, Total Verbal Tic Score, Total Tic Score (Motor + Verbal), Overall Impairment Rating, and Global Severity Score. When calculating the Global Severity score, it is found by adding together the total motor, verbal and impairment scores. The Total Tic Severity Score has a range of 0-50, and the Global Severity Score has a range of 0- 100. A higher score on all scales suggests a more severe Tic, or a greater impact the Tic has on the person's life. | 12 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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PEA, Palmitoylethanolamide, TS, Motor tics, Vocal tics, Cannabinoids, Dronabinol, Tourettes