An Algorithm for the Treatment of Chronic Pain with Cannabinoids
An Algorithm for the Treatment of Chronic Pain with Cannabinoids
An Algorithm for the Treatment of Chronic Pain with Cannabinoids
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<strong>An</strong> <strong>Algorithm</strong> <strong>for</strong> <strong>the</strong> <strong>Treatment</strong><strong>of</strong> <strong>Chronic</strong> <strong>Pain</strong> <strong>with</strong><strong>Cannabinoids</strong>John Clark MD FRCPCMedical DirectorCalgary Health Region <strong>Chronic</strong> <strong>Pain</strong>Centre
Disclosure•Valeant• Bayer
Objectives• To review an algorithm <strong>for</strong> <strong>the</strong>treatment <strong>of</strong> chronic pain <strong>with</strong>cannabinoids• Audience participation to discuss cases<strong>of</strong> intractable chronic pain wherecannabinoids might be considered
Case Discussion• 48 year old male, MVC 4 years ago• T 8 spinal fracture <strong>with</strong> incomplete spinal injury• <strong>Chronic</strong> pain– Radicular band at T 8-10 bilaterally– Left buttock and posterior thigh pain• Limited ambulation <strong>with</strong> crutches• Oxycontin 80 mg q 8hrs• Oxycodone 20 mg q 4 hrs prn (100 mg/day)• Failed TCAs and anticonvulsants
<strong>Algorithm</strong> – Step 1•Full assessment, establish diagnosis <strong>of</strong> pain•Assess psycho-social issues and risk <strong>of</strong> addiction•Determine history <strong>of</strong> previous use <strong>of</strong> illicit substances ormisuse <strong>of</strong> prescription drugs•Develop a treatment plan assuring that pharmaco<strong>the</strong>rapytakes place <strong>with</strong>in an overall active participatory approach•Assure that traditional approaches to chronic painmanagement have been tried or considered<strong>Pain</strong> is inadequately treatedStep 2
<strong>Algorithm</strong> – Step 2•Consider cautions and assure nocontraindications to use <strong>of</strong> cannabinoid•Discuss potential adverse effects•Consider discussing urine testing•Review and sign treatment agreementStep 3
<strong>Algorithm</strong> – Step 3Cannabinoid naïve:•Start an oral cannabinoidavailable by prescription *Previous use <strong>of</strong> cannabinoids:•Obtain a full history <strong>of</strong> previouscannabinoid use•Specific cannabinoid, dose, route<strong>of</strong> administration•Symptoms treated and outcome•Adverse effects•Encourage oral route
Dosing• Nabilone (Cesamet®)• Dronabinol (Marinol®)• THC:CBD (Sativex®)
Dosing• Cesamet®– Initiate at 0.5 mg orally at nite time– Increase dose by 0.5 mg every 2-3 days toa maximum dose <strong>of</strong> 2 mg orally twicedaily
Dosing• Cesamet®• Dronabinol®– Initiate at 2.5 mg orally at nite time– Increase dose by 2.5 mg every 2-3 days toa maximum dose <strong>of</strong> 10 mg twice dailyorally
Dosing• Cesamet®• Dronabinol®• Sativex®– 1-2 sprays first day, <strong>the</strong>n increase by 1-2sprays each day to effect/side effects– Product monograph - a maximum <strong>of</strong> 1spray every 4 hours on <strong>the</strong> first day
Has tried cannabis already…• 48 yr male <strong>with</strong> “failed low back surgerysyndrome” on fentanyl 50 ug/hr, gabapentin 800mg tid, no o<strong>the</strong>r medical problems, <strong>of</strong>f work.Smokes 1 pack/day• Tried nabilone, no effect and made him drowsy• Tried cannabis at a friend’s house recently…”bestpain relief ever”• What do you do now?
Heavy cannabis user…• 52 yr documentary producer <strong>with</strong> 10 year history<strong>of</strong> chronic foot pain following trauma. He claimsto have tried everything, nothing works except‘pot’. Uses 4g/day smoked and occasionally astea. No o<strong>the</strong>r meds. Works full-time. Examinationreveals clear tactile allodynia.• He asks you to sign medical marijuana access<strong>for</strong>ms• What do you do now?
<strong>Algorithm</strong> – Step 4 (Optional)If oral nabilone or THC trial fails or is not financiallyfeasible consider cannabis:•Discuss <strong>the</strong> fact that <strong>the</strong>re are not yet clear guidelinesregarding efficacy, doses and toxicity•Raise awareness <strong>of</strong> oral and vaporized routes <strong>of</strong>administration•Refer patient to Health Canada website and documentsregarding cannabis product•Follow <strong>the</strong> usual clinical guideline to start low and titratedose slowly
Recommendations(<strong>Pain</strong> Research & Management)Develop a treatment plan incorporating <strong>the</strong>se goals:• Reduction in pain• Increase functional abilities• Improved sleep quality• Increase quality <strong>of</strong> life• Reduction in <strong>the</strong> use <strong>of</strong> o<strong>the</strong>r medicationsEducate patient on:• Product nature• Potential benefits• Side effects• Discuss risk <strong>of</strong> addictionSource: Clark A.J. <strong>Cannabinoids</strong> <strong>for</strong> <strong>Pain</strong> Management. <strong>Pain</strong> Research & Management. Vol 10 Supplement A – Autumn 2005
Very heavy cannabis user…• 32 year old male, chronic low back pain <strong>with</strong>occasional sciatica <strong>for</strong> 4 years, on fentanyl 75ug,dilaudid 4mg qid prn, ativan 1mg tid, cannabis8g/day. Off work, no surgical options…• How do you manage this patient?
Thank you.
SummaryPharmaco<strong>the</strong>rapeutics and <strong>the</strong> nervoussystemCNSBrainDescending modulation<strong>An</strong>ticonvulsantsOpioids<strong>Cannabinoids</strong>Tricyclic/SNRI antidepressantsPNSPeripheralsensitizationSpinalcord<strong>An</strong>ticonvulsantsLocal anes<strong>the</strong>ticsOpioids<strong>Cannabinoids</strong>Topical analgesicsTricyclic antidepressantsCentral sensitization<strong>An</strong>ticonvulsantsNMDA-receptor antagonistsOpioids<strong>Cannabinoids</strong>Tricyclic/SNRI antidepressantsAdapted from Nicholson BD (2005)