Elon Eisenberg, EAN 2023: Clinician-based indications for cannabis-based medicine in patients with neuropathic pain

Prof Elon Eisenberg (Tachnion – Israel Institute of Technology, Haifa, Israel) summarizes our current knowledge on using cannabis in pain medicine, and the unmet needs in this field. He then provides some practical advice on using cannabis in clinical practice and offers his perspective on the next steps and what further studies are required.

The abstract ‘Cannabis-based medicine. Current evidence and clinician-based indications in patients with neuropathic pain’ was presented at the annual European Academy of Neurology (EAN), July 1–4, 2023

Questions

Disclosures: Elon Eisenberg is a consultant for Cannabotech; he has received grant/research support from Israel Pain Association, Rafa Laboratories, Syqe Medical and Teva Israel; he is a member of the Advisory Board for Rafa Laboratories, Syqe Medical and Vectura Ferin Pharma, and has received honoraria/honorarium from Rafa Laboratories and Syqe Medical.

Support: Interview and filming was supported by Touch Medical Media. The interview was conducted by Sophie Nickelson.

Filmed as highlight of EAN 2023.

Click here for more content in neuropathic pain

Transcript

My name is Elon Eisenberg. I’m a Professor of Neurology and Pain Medicine at the Faculty of Medicine, Technion, Israel, Institute of Technology in Haifa, Israel.

What are the current unmet needs in the treatment of neuropathic pain? (00:19)

In terms of treating neuropathic pain, this is entirely a huge unmet need. Because we know, again, based on randomized controlled trials, which is what we call evidence-based medicine, we know that the currently available medications are used or reduced 50% of the pain in about 1 to 3 or maybe 1 to 5 or 6 out of treated patients at best and those medications are associated sometimes with problems or adverse effects and tolerability, so patients usually do not adhere to them. The other part to that question or the answer to this question is that we haven’t had any new medications approved for use for neuropathic pain for almost two decades. So this is a major hole and what seems to be gradually, I would say, rolling in is cannabis, although, as I said before, the evidence regards its efficacy in terms of reducing the pain, the magnitude of pain reduction in response to the use of cannabis, does not seem to be a huge one, actually it’s a modest effect, and it doesn’t affect everybody.

Please summarize the current knowledge we have on the use of cannabis in medicine. (01:56)

First of all, we don’t talk only about cannabis-based medications or medicines, we talk about cannabis in general, which could be either medications or herbal cannabis. There are some differences between them but we don’t have to get into details. Now, the complexity of answering this question about which patients may benefit is really fairly confusing because in order to answer that, you need evidence and the evidence are really based on randomized controlled trials and randomized controlled trials yielded over the years mixed results, some showing that cannabis can be effective for neuropathic pain, not any specific subtype of neuropathic pain, but neuropathic pain in general, whereas other studies yielded conflicting results. But, overall, if you ask the International Association for the Study of Pain, which is the World Organization of Pain, they have not endorsed a recommendation to use medicinal cannabis for patients with chronic pain, whereas other organizations, like, for example, the European Pain Federation, suggests or allows to use or suggest you to consider using cannabis for selected patients with neuropathic pain.

What were the key take-home messages and practical advice from your presentation on this topic at the EAN 2023 annual meeting? (03:35)

There are a few. First, I’m not convincing anybody to use cannabis, I mean, to prescribe cannabis for your patients, I say please consider the available evidence. So this is one, please consider it and always consider the alternatives, I mean what else do you have available and at what cost, not financially, I’m talking about what costs in terms of effectiveness, efficacy, and safety. The second point is that we, as I said, tend to look at evidence based on randomized controlled trials, which are not convincing. But we if we look at cohort studies, at real life studies, which actually followed a considerable number of patients, in several studies, from different countries, patients have been followed for six months or a year or sometimes even more, and we do see an effect on pain, again, as a said, modest effect, but not only on pain, I mean on chronic pain, but also accompanying symptoms like depression, like anxiety, like sleep, they reduce these, again, all these modestly and they improve functioning and quality of life. The third take home message is that cannabis is not always innocent, there are side effects and adverse effects, it’s not good for everybody. Though you have to follow your patient if you decide to prescribe it and really make sure that you give it to the appropriate patient. For example, young males are at higher risk for having some psychotic evidence. It’s contraindicated in pregnant or lactating women, etc. So you have to keep that in mind and always follow your patient. There’s also some reports on cardiovascular effects. Next point, if you decide to prescribe it, please do not or avoid using smoked cannabis. We are really very much against it, against using smoked medicine, whatever, I mean smoking, in general, smoked medicine. The last point is that really we don’t have predictors. We do not know who is going to respond best, but if you have a patient with chronic pain who has not responded to reasonable treatment, so cannabis can be considered, and if you do that, please start at low dose and titre it gradually. So these are actually the take-home messages or the practical ones because some patients, not all, but some patients, clearly benefit dramatically from cannabis, and it seems to be the effect of cannabis on all these domains that I mentioned, it’s not the getting high, I mean please remember that most patients, even if they have chronic pain, they want to live a normal life. It’s like we, I mean, we sometimes drink alcohol, we could drink alcohol all day, but we don’t do it because we want to function, and we want to be able to do things, meaningful things, and the same is true for patients with chronic pain. There are not, many of them, some do, but most of them do not look for the high effect of the cannabis. They are truly generally looking for something that will help all these domains, including pain, and for some of them, it can work, so don’t exclude it automatically without really considering it deeply.

What are the next steps and further studies required in this field? (07:37)

Again, since cannabis is a complex herb with many constituents, randomized controlled trials do not seem to be the way or, based on our current knowledge, we cannot really come or get firm conclusions about its efficacy based on randomized controlled trials. We need other types of studies, studies which are called pragmatic studies, in order for us to understand which components of the cannabis can suit which patient, and, doing this kind of studies, based on that, in the future, we’ll likely be able to conduct much more sophisticated randomized controlled trials, which will eventually give us the response that we are looking for, scientifically, but there is a long way to go still.