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Practice Rapid Recommendations

Medical cannabis or cannabinoids for chronic pain: a clinical practice guideline

BMJ 2021; 374 doi: https://doi.org/10.1136/bmj.n2040 (Published 09 September 2021) Cite this as: BMJ 2021;374:n2040

Visual summary of recommendation

Interventions compared or Cannabis Standard care plus a trial of non-inhaled medicalcannabis or cannabinoids Standard care No trial of medical cannabisor cannaninoids
Population This recommendation applies only to people with these characteristics: All patients living with moderate to severe chronic pain Applies to people with: Cancer and non-cancer pain May or may not apply to: Paediatric populations Does not apply to: Inhaled medical cannabis Recreational cannabis Patients receiving end of life care Veterans Patients with concurrent mental illness Patients receiving disability benefits or involved in litigation Neuropathic pain, nociceptive pain, and nociplastic pain
Recommendation
Standard careCannabisorPeople living with chroniccancer or non-cancer painIf standard care is not sufficient, we suggestoffering a trial of non-inhaled medical cannabisor cannabinoidsStrongAll or nearly all informed people would likelywant the intervention to the left. Benefitswould outweigh harms for almost everyoneWeakMost people would likely want the interventionto the left. Benefits would outweigh harms forthe majority, but not for everyoneWeakMost people would likely want the interventionto the right. Benefits would outweigh harmsfor the majority, but not for everyoneStrongAll or nearly all informed people would likelywant the intervention to the right. Benefitswould outweigh harms for almost everyone

Evidence profile

Favours standard careFavours cannabisNo important differenceThe panel found that this difference was not important for most patients,because the intervention effects were negligible and/or very imprecise, forexample confidence intervals that include both important benefit and harm
Potential benefits
1 to 4 monthsEvents per 1000 peopleEvidence quality

Reduction in pain100 more520620ModerateMore

Based on data from 3939 patients in 27 studiesUse of medical cannabis or cannabinoidsprobably results in a small increase inthe proportion of patients experiencingan important reduction in painMID1cmThe “minimally important difference” forpatients was defined as an improvementof 1 cm on a 10 cm visual analogue scaleModerateGRADE rating,because of:Risk of biasNo serious concernsImprecisionNo serious concernsIndirectnessNo serious concernsInconsistencySeriousPublication biasNo serious concernsGRADE certainty ratingsHighThe authors have a lot ofconfidence that the trueeffect is similar to theestimated effectModerateThe authors believe thatthe true effect is probablyclose to theestimated effectLowThe true effect might bemarkedly different fromthe estimated effectVery lowThe true effect isprobably markedlydifferent from theestimated effect

Improved physical function40 more280320HighMore

Based on data from 2425 patients in 15 studiesUse of medical cannabis or cannabinoidsresults in a very small increase in theproportion of patients experiencing animportant improvement in physicalfunctioningMID10The “minimally important difference” forpatients was defined as an improvementof 10 points on a 0-100 point SF-36physical functioning subscaleHighGRADE rating,because of:Risk of biasNo serious concernsImprecisionNo serious concernsIndirectnessNo serious concernsInconsistencyNo serious concernsPublication biasNo serious concernsGRADE certainty ratingsHighThe authors have a lot ofconfidence that the trueeffect is similar to theestimated effectModerateThe authors believe thatthe true effect is probablyclose to theestimated effectLowThe true effect might bemarkedly different fromthe estimated effectVery lowThe true effect isprobably markedlydifferent from theestimated effect

Improved emotional functionNo important difference310330HighMore

Based on data from 2115 patients in 10 studiesUse of medical cannabis or cannabinoidsdoes not improve emotional functioningMID10The “minimally important difference” forpatients was defined as an improvementof 10 points on a 0-100 point SF-36emotional functioning subscaleHighGRADE rating,because of:Risk of biasNo serious concernsImprecisionNo serious concernsIndirectnessNo serious concernsInconsistencyNo serious concernsPublication biasNo serious concernsGRADE certainty ratingsHighThe authors have a lot ofconfidence that the trueeffect is similar to theestimated effectModerateThe authors believe thatthe true effect is probablyclose to theestimated effectLowThe true effect might bemarkedly different fromthe estimated effectVery lowThe true effect isprobably markedlydifferent from theestimated effect
1 to 3.5 monthsEvents per 1000 peopleEvidence quality

Improved role functionNo important difference410410HighMore

Based on data from 1128 patients in 7 studiesUse of medical cannabis or cannabinoidsdoes not improve role functioningMID10The “minimally important difference” forpatients was defined as an improvementof 10 points on a 0-100 point SF-36physical role functioning subscaleHighGRADE rating,because of:Risk of biasNo serious concernsImprecisionNo serious concernsIndirectnessNo serious concernsInconsistencyNo serious concernsPublication biasNo serious concernsGRADE certainty ratingsHighThe authors have a lot ofconfidence that the trueeffect is similar to theestimated effectModerateThe authors believe thatthe true effect is probablyclose to theestimated effectLowThe true effect might bemarkedly different fromthe estimated effectVery lowThe true effect isprobably markedlydifferent from theestimated effect

Improved social functionNo important difference390380HighMore

Based on data from 1405 patients in 8 studiesUse of medical cannabis or cannabinoidsdoes not improve social functioningMID10The “minimally important difference” forpatients was defined as an improvementof 10 points on a 0-100 point SF-36social role functioning subscaleHighGRADE rating,because of:Risk of biasNo serious concernsImprecisionNo serious concernsIndirectnessNo serious concernsInconsistencyNo serious concernsPublication biasNo serious concernsGRADE certainty ratingsHighThe authors have a lot ofconfidence that the trueeffect is similar to theestimated effectModerateThe authors believe thatthe true effect is probablyclose to theestimated effectLowThe true effect might bemarkedly different fromthe estimated effectVery lowThe true effect isprobably markedlydifferent from theestimated effect
1.3 to 3.5 monthsEvents per 1000 peopleEvidence quality

Improved sleep quality60 more480540HighMore

Based on data from 2652 patients in 9 studiesUse of medical cannabis or cannabinoidsresults in a small increase in theproportion of patients experiencingimproved sleep qualityMID1cmThe “minimally important difference” forpatients was defined as an improvementof 1 cm on a 10 cm visual analogue scaleHighGRADE rating,because of:Risk of biasNo serious concernsImprecisionNo serious concernsIndirectnessNo serious concernsInconsistencyNo serious concernsPublication biasNo serious concernsGRADE certainty ratingsHighThe authors have a lot ofconfidence that the trueeffect is similar to theestimated effectModerateThe authors believe thatthe true effect is probablyclose to theestimated effectLowThe true effect might bemarkedly different fromthe estimated effectVery lowThe true effect isprobably markedlydifferent from theestimated effect
Potential short term harms
1.3 to 3.5 monthsEvents per 1000 peopleEvidence quality

Cognitive impairment20 fewer1030ModerateMore

Based on data from 1033 patients in 5 studiesUse of medical cannabis or cannabinoidsprobably results in a small increase inthe proportion of patients experiencingcognitive impairmentModerateGRADE rating,because of:Risk of biasNo serious concernsImprecisionSeriousIndirectnessNo serious concernsInconsistencyNo serious concernsPublication biasNo serious concernsGRADE certainty ratingsHighThe authors have a lot ofconfidence that the trueeffect is similar to theestimated effectModerateThe authors believe thatthe true effect is probablyclose to theestimated effectLowThe true effect might bemarkedly different fromthe estimated effectVery lowThe true effect isprobably markedlydifferent from theestimated effect
1 to 3.5 monthsEvents per 1000 peopleEvidence quality

Drowsiness50 fewer4090ModerateMore

Based on data from 2505 patients in 15 studiesUse of medical cannabis or cannabinoidsprobably results in a small increase inthe proportion of patients experiencingdrowsinessModerateGRADE rating,because of:Risk of biasNo serious concernsImprecisionSeriousIndirectnessNo serious concernsInconsistencyNo serious concernsPublication biasNo serious concernsGRADE certainty ratingsHighThe authors have a lot ofconfidence that the trueeffect is similar to theestimated effectModerateThe authors believe thatthe true effect is probablyclose to theestimated effectLowThe true effect might bemarkedly different fromthe estimated effectVery lowThe true effect isprobably markedlydifferent from theestimated effect
1 to 4 monthsEvents per 1000 peopleEvidence quality

Impaired attention30 fewer1040ModerateMore

Based on data from 895 patients in 7 studiesUse of medical cannabis or cannabinoidsprobably results in a small increase inthe proportion of patients experiencingimpaired attentionModerateGRADE rating,because of:Risk of biasNo serious concernsImprecisionSeriousIndirectnessNo serious concernsInconsistencyNo serious concernsPublication biasNo serious concernsGRADE certainty ratingsHighThe authors have a lot ofconfidence that the trueeffect is similar to theestimated effectModerateThe authors believe thatthe true effect is probablyclose to theestimated effectLowThe true effect might bemarkedly different fromthe estimated effectVery lowThe true effect isprobably markedlydifferent from theestimated effect
See all outcomes
Patient decision aids

Individual considerations

Key practical issues The weak recommendation reflects a high value placed on small to very small improvements in self reported pain intensity, physical functioning, and sleep quality, and willingness to accept a small to modest risk of mostly self limited and transient harms Values and preferences Cannabis Standard care Therapeutic trials should start with low dose, non-inhaled cannabidiol products, gradually increasing the dose and tetrahydrocannabinol level depending on clinical response and tolerability Prior cannabis experience should be considered, and adverse events should be carefully monitored For younger or adolescent patients, cannabidiol-predominant preparations should be preferred, because of uncertain effects of tetrahydrocannabinol on neurocognitive development Patients should avoid driving or operating machinery while starting or changing dose of medical cannabis Women contemplating pregnancy, pregnant women, or women who are breast feeding should be encouraged to discontinue use of medical cannabis in favour of alternative therapy No additional practical issues

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