Pain intensity of chronic non-cancer patients was reduced by cannabinoids consumption , but effect sizes were small .
Efficacy for neuropathic and non-neuropathic pain was similar
There is growing interest in using cannabinoids for chronic pain .
We performed a systematic review and meta- analysis of r and omized controlled trials to evaluate the analgesic efficacy and adverse effects of cannabinoids for chronic non-cancer pain .
Medical Marijuana: Is the Cart Before the Horse?
There is apressingneed todevelopnewmedications formany debilitating conditions . Novel approaches based onmarijuana or its constituent cannabinoids , if proven , could be added to the armamentarium of available treatments . In this issue of JAMA , review s byWhiting et al1 and Hill2 provide detailed assessment of thepharmacology , indications , benefits , adverseeffects , and laws related tomedicalmarijuana and thecannabinoids , and the results and conclusions are consistent . There is some evidence to support the use of marijuana for nausea and vomiting related tochemotherapy , specificpain syndromes , and spasticity from multiple sclerosis . However , for most other indications that qualifyby state lawforuseofmedicalmarijuana , suchashepatitis C , Crohn disease , Parkinson disease , or Tourette syndrome , the evidence supporting its use is of poor quality . State laws vary widely regarding conditions for which marijuana is approved and thedispensable legal limit . Both review sraise important issues worthy of further discussion . First , for most qualifying conditions , approval has relied on low- quality scientific evidence , anecdotal reports , individual testimonials , legislative initiatives , and public opinion . Imagine if other drugs were approved through a similar approach . The US Food and Drug Administration ( FDA ) requires evidence from at least 2 adequately powered r and omized clinical trials before approving a drug for any specific indication . For most of the conditions that qualify for medical marijuanause , the evidence fails tomeet FDA st and ards . It has beenargued that the lackof high- quality evidence reflects the difficulty inconductingmarijuana research intheUnitedStates . If so , the federal and state governments should support and encourage such research so that high- quality evidence canbe generated to guidedecisions aboutmedicalmarijuanause for the conditions forwhich the existing evidence is either insufficient or of poor quality . Second , there are inconsistencies in how medical conditionsarequalified formedicalmarijuanausewithina state and between states . For example , in Connecticut , psoriasis and sickle cell disease but not Tourette syndrome qualify , even though the supporting evidence for all 3 conditions is uniformly of very low quality . Similarly , posttraumatic stress disorder ( PTSD ) is approvedas aqualifying condition in somebut not all US states . These differences reflect inconsistencies in evaluating and applyingcurrent evidence towarddecisionmaking about qualifying indications for medical marijuana use . Third , unlikemost FDA -approveddrugs that typicallyhave 1or2activeconstituents , marijuanaisacomplexofmorethan400 compounds including flavonoids and terpenoids and approximately 70 cannabinoids other than Δ9-tetrahydrocannabinol (THC)3.Thesecannabinoidshaveindividual , interactive , and even entourageeffects(effectsofacompoundthatareonlyappreciable inthepresenceofothercompounds)thatarenotfullyunderstood and thatcontributetotheneteffectofmarijuana . Although clinical trials forsomeof thequalifyingconditions and studies inanimalmodelsof thoseconditionshavebeenconductedwith individual cannabinoids ( eg , THCor cannabidiol [ CBD ] ) , given that marijuanahas somanyconstituents , the results of studies with individualcannabinoids(eg , THCorCBD)cannotbeextrapolated tomarijuana and vice versa . In addition , unlike FDA -approved medicationsthathavearelativelyuniformcomposition , thecompositionofcannabispreparationscanvarysubstantiallyinitscontent of THC and CBD , such that precise dosingmaybe difficult . Giventhevariablecomposition , patients willhavetoexperiment with different strains and doses to achieve the desired effects , withoutmuch input or oversight by physicians . Fourth , some individual cannabinoids are already commercially available in the form of dronabinol and nabilone . Thesedrugs are administeredorally , and somepublished data are available to guide dosing . In contrast , there are few data on dosing smoked medical marijuana for many of the qualifying medical conditions for which it is used . Fifth , while theacuteadverseeffectsofmarijuanaarequite well known , the effects of repeated exposure , aswould occur withmedicalmarijuana , need further study . Approximately 1 in 10 adult users of marijuana  develops addiction , and this number is evenhigher amongadolescents.4Tolerance and dependence with accompanying down-regulation and desensitization of type 1 cannabinoid receptors occur with repeated exposure.5 Based on this profile , marijuana dosing will have to be increased over time to achieve the same effect . A distinct withdrawal syndrome is also well recognized . There is also a small but definite risk of psychotic disorder associated with marijuana use , as well as a significant risk of symptom exacerbations and relapse in patients with an establishedpsychoticdisorder.6Thus , explicitcontraindicationssuch as schizophrenia , bipolar disorder , or substance dependence need tobe identifiedalongwith measures tominimize the likelihoodthatpersonswithcontraindicationswouldbeable toobtain medical marijuana . Perhaps US states should establish clinical follow-upprogramstomonitor long-term outcomes prospect ively , especiallynegative outcomes ( eg , newcasesofpsychosis ) in patients with contraindications . Author Audio Interview at
Pain intensity of chronic non-cancer patients was reduced by cannabinoids consumption , but effect sizes were small .
Efficacy for neuropathic and non-neuropathic pain was similar
There is growing interest in using cannabinoids for chronic pain .
We performed a systematic review and meta- analysis of r and omized controlled trials to evaluate the analgesic efficacy and adverse effects of cannabinoids for chronic non-cancer pain .