Nabilone and THC/CBD for the Treatment of FBSS Refractory Pain

Study Overview
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Brief Summary
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The aim of this study is to evaluate the efficacy of oral administration of nabilone or THC/CBD administration in combination with spinal cord stimulation (SCS) in FBSS patients refractory to other available therapeutic strategies.

Detailed Description
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Failed Back Surgery Syndrome (FBSS) is defined as: spinal pain of unknown origin either persisting despite surgical intervention or appearing after surgical intervention for spinal pain originally in the same topographical location. Several conditions have been identified as causes of FBSS: epidural fibrosis, canal stenosis (global or lateral), foraminal stenosis, retained disc fragment, recurrent disc herniation or degeneration, spinal instability, facet joint pain, sacroiliac joint pain, discitis, adhesive arachnoiditis and others. Can involve 20% to 40% of patients who have undergone lumbar spine surgery and 0.02% to 2% of the general population suffer from this syndrome. In FBSS symptoms are the persistence of low back pain, deterioration or recurrence of radiculopathy, sensory and/or motor deficit, sphincter dysfunction. Chronic opioid therapy does not improve long-term pain management. Similar issues can occur with conservative measures like peridural injections of steroids, intrathecal analgesic infusion and local anesthetics injections. Despite a large part of FBSS patients benefit of radio-frequency treatment and/or spinal cord stimulation (SCS), a small percentage of them doesn't report benefits. Pain could be treated by drugs modulating endocannabinoid system and it could represent a pharmacological option in a multimodal treatment approach for neuropathic pain. Authors present a retrospective case series documenting the efficacy and safety of oral administration of cannabinoids agonists (THC/CBD and nabilone) in 20 FBSS patients, presenting moderate to severe chronic pain that not responding to other treatment regimens. Cannabinoids agonists were administered in association with the practice of spinal cord stimulation (SCS). Other analgesic therapies were discontinued before the beginning of the treatment. The study was performed during the period between September 2014 and January 2016 and the duration was up to 12 months. Characteristics and severity of neuropathic pain were measured using the Douleur Neuropathique 4 questionnaire. The Brief Pain Inventory allows patients to rate the severity of their pain and the degree to which pain interferes with common dimensions of feeling and function. Patients aged between 45 and 69. All patients received a fixed dose of cannabinoid agonists: treatment was initiated with nabilone 1mg/day or an oleic suspension for oral administration of THC/CBD 25mg/day. The basal dose was increased depending on effects on pain control. Adverse reactions were treated by decreasing the subscripted dose. If adverse events required the suspension of the administration of the initially prescribed drug, the same was switched with the other available in the study.

Official Title
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Nabilone and THC/CBD for the Treatment of FBSS Refractory Pain

Conditions
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FBSS

Intervention / Treatment
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* Drug: Nabilone
* Drug: THC/CBD


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: FBSS with refractory pain DN-4 score of 4 or + Exclusion Criteria: Adverse Drug Reaction Subject suffers from FBSS that could not quit the previous pharmacological therapy

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 70 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Nabilone<br>Patients affected by Failed Back Surgery Syndrome (FBSS) | Drug: Nabilone<br> <br> * Other names: Spinal Cord Stimulation;|
| THC/CBD<br>Patients affected by Failed Back Surgery Syndrome (FBSS) | Drug: THC/CBD<br> <br> * Other names: Spinal Cord Stimulation;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Brief Pain Inventory (BPI) | The Brief Pain Inventory allows patients to rate the severity of their pain and the degree to which their pain interferes with common dimensions of feeling and function. BPI has been shown to be an appropriate measure for pain caused by a wide range of clinical conditions. The BPI is an 11-item questionnaire that consists of four 0- to-10 numeric rating scale (NRS) items asking patients to rate their pain at its worst in the last 24-hours, least in the last 24-hours, average, and now, with a 0 indicating no pain and 10 representing pain as bad as you could imagine. The remaining seven BPI items probe the degree to which pain interferes with general activity, mood, walking ability, normal work, relations with other people, sleep, and enjoyment of life, again using a 0-to-10 value scale. For these interference items, 0 represents does not interfere and 10 indicates interferes completely. | 2015/1 to 2016/1 | 
| Douleur Neuropathique-4 (DN-4) | The DN4 questionnaire consists of a total of 10 items: 7 items related to the characteristics of pain (burning, painful cold, electric shocks) and its association with abnormal sensations (tingling, pins and needles, numbness, itching), and 3 related to neurological examination in the painful area (touch hypesthesia, pinprick hypesthesia, tactile allodynia). The value of 1 was given to each positive item, and 0 value to each negative item. The total score was calculated as the sum of all 10 items and the cutoff value for the diagnosis of neuropathic pain is established as a total score of 4/10. | 2015/1 to 2016/1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cannabinoids, nabilone, FBSS, THC/CBD, refractory pain