The role of cannabinoid-based medicines in pain management

  • Silviu Brill

    Director of Institute of Pain Medicine, Tel Aviv Medical Center, Israel
  • Winfried Häuser

    Adjunct Professor, Department Psychosomatic Medicine and Psychotherapy, Technical University Munich, Germany Senior Physician, Department Internal Medicine, Germany

Chair: Silviu Brill, Israel
Speaker: Winfried Häuser, Germany
The topic of this lecture is a semantic, methodological and political minefield. 

Semantics: the plethora of terminologies used to define cannabis-derived medications in the public and scientfic domain has caused confusion and runs the risk that all cannabis-derived medications are labelled as cannabis“. Cannabis is a collective term for substances derived from the female hemp plant of the genus Cannabis sativa. Cannabinoids, in turn, are a collective term for substances derived from the resin of the hemp plant that can modulate the endocannbinoid system. The female hemp plant contains more than 100 phytocannabinoids, with tetrahydrocannabinol (THC) and cannabidiol (CBD) best characterized.  

1. Medical cannabis is available as cannabis flowers and cannabis oils with a defined content of tetrahydrocannabinol (THC) and cannabidiol (CBD). In addition, these products contain other molecules including phytocannabinoids, terpenes and flavionoids. The concentrations of these other substances are not or only poorly identified in medical cannabis products.

2. Cannabinoid-based medicines (CBM) 

2.1 Formulated medicinal products containing defined doses of cannabinoids:
  • A THC/CBD-containing oromucosal spray identified as nabiximols (Sativex ©) 
  • An oral solution of CBD (Epidiolex). 
  • A tablet of a synthetic THC analog (nabilone)  

2.2. Extemperaneous mixtures containing defined doses of cannabinoids extracted from the cannabis plant:Oral solutions and tablets with THC (Dronabinol ©)  

It is notable that most randomised controlled trials (RCT’s) for pain mangement have been conducted with cannabinoid-based medicines and not with medical cannabis.  

Methodology and politics: In the pain community, there are highly polarized views about the indications for use, as well as the efficacy and safety of cannabinoid-based medicines and medical cannabis. Currently, there are a limited number of RCT’s for various pain-related conditions, with the numbers of trials exceeded by the number of systematic reviews. Conclusions of systematic reviews, either positive or negative are the foundation of evidence-based medicine and should be the driver for patient care. Divergent conclusions of SRs on the efficacy of cannabis-based medicines in chronic pain may be attributed to analyses of different studies based on different inclusion criteria, variable study duration, and differing attributes of benefits and risks. A recent systematic overview of systematic reviews concluded that current systematic reviews are mostly lacking in quality and cannot provide a basis for decision-making. The same author group concluded that even when including their own systematic review of RCTs, the evidence neither supports nor refutes claims of efficacy and safety for cannabinoids, cannabis, or CBM in the management of pain. Unfortunately, adhering to this rigorous methodology is not helpful in clincial practice. In my lecture I will discuss the evidence available for use (e.g. neuropathic pain) and not for use (e.g. cancer pain insufficiently controlled by opioids) of cannabinoid-based medicines and medical cannabis in general. In addition, I will list the evidence available on harms of cannabinoid-based medicines and medical cannabis.


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