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Cannabis and Cancer Care with Dr. Katia Tonkin

Cannabis and Cancer Care with Dr. Katia Tonkin

Dr. Vaughn talks with Oncologist and Society of Cannabis Clinicians board member Dr. Katia Tonkin about the changing role of cannabis in cancer care and pain management. Listen now to go behind the diagnosis and learn more about the medical use of cannabis and best practices in clinical care.

Dr Vaughn: Welcome to Cancer Shop Talk, Behind the Diagnosis.  Today’s episode begins our new series on Medical Cannabis.  We’re connecting with providers, subject matter experts, and patients to go behind medical cannabis and uncover how the treatment is used when it comes to oncology.  Today we’re thrilled to welcome Dr. Katia Tonkin to the show.

Dr. Vaughn: Well, I am really excited.  We’re going to talk about cannabis and how it has really become a hot button item in the landscape of oncology.  I know I get asked about it a lot.  And so, I’m very thrilled to have a special guest all the way from Canada.  Dr. Katia Tonkin from Canada is going to help educate us today.  I will say from my podcast, you are by far the farthest location so far I have interviewed.  So, I am really excited and so honored to have you on, Dr. Tonkin.  I just wanted to allow you some time to introduce yourself and really kind of what steered you in this kind of direction of cannabis awareness and some of the potential therapeutic benefits it has in oncology.

Dr. Tonkin: Thanks very much for inviting me.  I realize I’m from the far north, but I’m also English, and I’m a medical oncologist who’s got a dual training from the UK and also from Canada, but I’ve spent virtually all of my professional life here in Canada. Hanging on to this British accent has been hard work.  But as a medical oncologist, as you well know, Dr. Vaughn, you’re always asked about complimentary therapy or alternative therapy, the difference being complimentary is they want to take something alongside what you’re prescribing, and alternative means they want to do something instead of.  

And I started to be asked about cannabis, like I’ve been asked about many, many other things over my career, and I began to, you know, want to look into it in greater depth.  And I decided actually to make a switch in 2017 and actually just not to be a medical oncologist anymore and actually just focus on cannabis.  And I did that because I recognized that cannabis is a really interesting drug for many problems that patients have, not a cure all, but many of the problems that cancer patients have such as pain, insomnia, anxiety, and depression, are very common with many patients with all sorts of arthritis problems, et cetera.  And also, I wanted, at this stage of my career, not to work full-time anymore.  

And so, this was an ideal way to take something I thought was at the beginning of being something very academic and very interesting, but something I could do on a part-time basis, which is hard when I was an academic medical oncologist.  I’m a professor at the University of Alberta here, now professor emeritus cause I’ve retired from, you know, my full-time job.  So, you know, I’ve got over 80 publications, so I’ve been very academic, so I’m looking at cannabis from that academic point of view.  And I think there’s wonderful things that are being done, and I think there’s, you know, a lot more wonderful things that we can be doing in the future.

Dr. Vaughn: Was it a point in time where you thought is cannabis going to become, like you mentioned, is it going to be a complimentary thing in the future or is it going to replace treatment for certain things?  How do you – where do you think it’s going to – I guess get its role in oncology treatment?

Dr. Tonkin: I mean as you well know in oncology, we generally use a cocktail of drugs.  I mean there were some times, some indications, where we use one drug, but we often use a cocktail.  And I feel cannabis has got basically two potential roles.  One is to help with symptom control, in order that we can give a good dose of the treatment we want to give.  And it’s not only chemotherapy, as you know, it’s the other treatments that we now give that often have some pretty miserable side effects.  But systemic therapy can sometimes be difficult to tolerate.  So, if cannabis can help patients tolerate their treatment, it means you’re able to give a better outcome by using the combination in that way.  

And the second option is that like we’ve added two or three drugs to make a combination, sometimes we’ve added a fourth drug to make a combination.  In some instances, I think there will be some diseases where we will add cannabis as a treatment option.  I don’t think on its own, but I think alongside some other things.  So, the sort of trials we might do would be everybody gets the three-drug combination, and then half of the patients will get the cannabis added to that.  

So, that’s the kind of way I see it. On the one hand to help symptoms so that we can prescribe our systemic therapy to a level that we want to, but we sometimes can’t because of side effects, and then as a new addition to the current therapy for some cancers as an actual treatment modality.

Dr. Vaughn: Especially in our office and practice here and really throughout the United States, there’s been a big shift into a palliative care treatment, and meaning – that doesn’t mean we’re, you know, transitioning to hospice or comfort measures.  We try to constantly highlight that with our patients who think palliative care means, you know, end of life care.  But no, really to kind of palliate the side effects and symptoms of their disease, and I wonder – and we have our own sort of palliative care clinic in the office.  

You know, patients, for instance, it’s been a big mission of ours, diagnosed with Stage 4 lung cancer and there’s a lot of side effects to treatment, a lot of discussion, you know, like appetite, you know, the pain, and I can imagine this really becoming maybe a center point, you know, cannabis as far as a palliative care approach, you know, as you mentioned, a compliment to the patient’s own treatment.

Dr. Tonkin: I’ve always had difficulty with the word “palliative” because as you obviously just said, it makes people think that’s end of life, the last three months and then I’m done.  And I used to try and – when residents would come through and a patient came to their first metastatic visit, and they said, “Well I told them they were palliative,” I said, “No, no, no, no, no, because then the poor patient is going to think they’re already done for” you know. 

And so, I used to say it’s treatable but not curable.  And when you think of most diseases in internal medicine, I mean rheumatoid arthritis or any of the other arthritis, you know, heart disease, we don’t cure heart disease, we treat it.  Diabetes, we don’t cure it, we treat it.  If you want to have something cured, you go and have your gall bladder taken out.  

So, you know, I think they need to have a mind set that this may be a chronic disease and we’re just trying to give you the best quality of life, give you the best treatment we can give you and make your quality of life bearable.  And if we have to keep dose reducing because you can’t tolerate it, which is sometimes a genetic – it’s a pharmacogenomic thing, your metabolism for that drug just may be that you need a half dose or a three-quarter dose.  But if we can actually sustain you on your chemotherapy better because we’re using other treatments such as cannabis, that’s great.  

There are a couple of issues with cannabis that are really important, and one is with the immune checkpoint inhibitors.  And that’s why it’s important when you’re talking about  lung cancer, because some of the drugs that are now used like Nivolumab, that’s actually had a good study that shows that survival is negatively impacted if you mix cannabis with Nivolumab.  So immune checkpoint inhibitors, it doesn’t mean to say anyone with monoclonal antibodies, but the immune checkpoint inhibitors, I would not want to give a patient cannabis if they’re getting that treatment.  

Dr. Vaughn: That is fascinating, Dr. Tonkin.  Is that information that is – 

Dr. Tonkin: Yeah, it’s published.

Dr. Vaughn: Published it and – 

Dr. Tonkin: It’s published.

Dr. Vaughn: It is?  Okay.

Dr. Tonkin: Yeah.  So, if you look up Nivolumab and cannabis, you can actually find that paper.  It comes out of Israel, and originally, they said it just affected response rate, but now they updated it and it definitely affects survival, so that – so immune checkpoint inhibitors are to me a no-no with cannabis.  And it’s awkward, because sometimes for side effects it’s thought the cannabis would be helpful, but then when you discuss it with a patient and you say well look, here’s the problem, in your particular case I don’t know whether you would be negatively impacted from your survival, but I don’t want to take that risk for you.  

And then other drugs like Tamoxifen, which is a prodrug and of course we use it still a lot in breast cancer, there are concerns with cannabis, but it’s a little bit unclear whether that’s going to be an issue or not.  But there’s definitely concerns because of the SYP enzymes, the 3A4 and the 450 which are to do with THC and CBD metabolism.  Again, so many women stopped taking their Tamoxifen or their own aromatase inhibitor well before the five years, because they can’t tolerate it.  Which is better?  That you give them just a little tad of cannabis so that they can actually take the drug for the five to 10 years, or they quit at two years.  I mean that’s a tough question, right?

So, all the time we’re making those balance judgments, because most patients believe that cannabis, because it comes from a plant, is harmless.  You and I know that most chemo drugs come from plants, and they’re clearly not harmless.  So, when patients come to the office and see me, they say, “Well I want something that’s natural,” but natural isn’t harmless, and you have to look at these interactions.  Even with, for example, hypnotics, benzodiazepines, et cetera, or even antidepressants.  There are technically interactions with cannabis so if patients want to use less of their temazepam to sleep or less of their – even opioids, you have to do a little balancing act.  

But the people don’t realize that you have your own cannabis.  You have an anandamide and 2AG, you have indogenous cannabinoids.  So, you have cannabis receptors, CB1 and 2, head to toe, the same as you have opioid receptors, which patients don’t realize either, right, because you have those endorphins, that runners’ high.  And those two sets of receptors actually crosstalk.  So, if patients want to come down on their opioids as we increase their cannabis, it’s actually not too difficult to do, and there’s a huge Israeli study of almost 3,000 patients where 36 percent, about 344 patients were on opioids and 36 percent of those were able to reduce their opioids and 10 percent actually came off.  And those are all cancer patients.  

So, you know, there are lots of things we can do with cannabis, but patients have to understand, and I always explain, “It’s a drug.”  It may be a plant-based drug, but it’s still a drug.  So, you have to consider, you know, how we metabolize it and genetically, how you metabolize like any drug.  Some people are fast metabolizers, average or slow metabolizers.  The same is true for cannabis.  So, there are all these very interesting scientific elements to cannabis, which the average patient just says “it’s natural” and that’s why I want it.

Dr. Vaughn: And one of the questions that comes up, and you were alluding to that, is you know, how do I know, you know, we’re so used to giving like, you know, an oral ACE inhibitor, it’s a once-a-day drug or we give some of our oral oncolytics are twice a day dosing.  We know the therapeutics, the kinetics.  I get asked how often do I take, you know, medical cannabis?  Do I smoke it?  Are edibles better?  And I know that confuses providers, so when you go out and you educate providers, how do you answer those questions?

Dr. Tonkin: Yeah, as an oncologist, I don’t believe you should put anything in your lungs apart from fresh air and if you have an inhaler that your doctor gives you because you’ve got asthma or COPD, and that’s just very basic, right?  Theoretically, vaporization is better because it’s got a lower combustion temperature.  I don’t like the idea of vaporizing oil, because obviously we know that the last thing that you want to put in your lung is oil.  It’s like popcorn lung, and this has got to be a bad thing, right?  So, I try and steer people away from smoking and vaping.  

The big advantage of smoking or vaping is that because it goes into the lungs and into the bloodstream, it kicks in very quickly.  So, it’s like your short acting pain killer or your short acting anti-anxiety medication.  The minute you ingest it through your stomach, it’s got to go through the liver and be activated.  So, if you do it at the same time, let’s say you vape and then you take something by mouth, then you’ve got your short acting and long acting you take at the same time.  And so that is not a bad combination, but if you’re not used to vaping or smoking, then most patients don’t even want to try it which is good, you know, is fine by me.  

And then that just means that they have to take like you would any pain killer or anxiety medication, a steady level of it so that you don’t let either the pain or the anxiety, you know, break through.  So, in terms of what we usually do is we usually start people on oils.  You know, it’s always got a mantra, “go slow, go low,” so that’s like saying, you know, try a quarter of an aspirin, then a half an aspirin, then three-quarters, you know, so you wouldn’t say to somebody the first thing you do in pain is try six aspirins in one dose or six Tylenol or whatever.  You just wouldn’t do it.  So, you go slow.  

And then as you gradually build up, you’re trying to figure out, okay, if there’s one drug that you hate, let’s say you’ve got, you know, you’re on an opioid, so let’s say you’re taking a lot of breakthrough opioid.  Let’s see as we build up your cannabis during the day, or CBD mainly during the day so that we don’t make you high with the THC.  THC stands for The High Compound.  That’s how I explain it.  It’s not actually what it stands for, but it’s actually quite a good acronym.  And so, as you gradually increase the CBD during the day, you see well are you taking less breakthroughs.  

Obviously, we don’t, you know, we hope that by giving long-acting opioids they don’t need breakthroughs.  But obviously, you know, from time to time if they’re having a tough day or something they do.  So, you need a little bit of a sort of diary to see well are we now getting to the point where instead of on average you’re taking four or five breakthroughs a week or one or two a day, you’re pretty well taking none, then we’re in a good situation.  Then we can start to reduce your long-acting opioids as we increase, you know, your cannabis even more.  

And generally speaking, if you end up with some of each, most people will feel better on some cannabis and less opioids, because I mean I used to hand out opioids a lot when I practiced medical oncology full-time, and we accepted that they had some miserable side effects.  But most people, if you can reduce their opioids and substitute at least some of it with cannabis, they actually feel better.  Because chronic opioids are actually not much fun.  It’s really not a very nice drug.  People really don’t like to be on it.  

Dr. Vaughn: No, and we’re so used to just prescribing it, right?

Dr. Tonkin: Yes.

Dr. Vaughn: You know, again, it’s just something we got used to doing and prescribing and that’s how we deal with pain, but there’s so many side effects to it, you’re so right.  I love being able to give something that’s going to reduce the amount of, you know, the constipation with opioids.

Dr. Tonkin: Exactly.

Dr. Vaughn: And the lethargy and ability – and especially when we’re talking about pain to go to patients if they can spend quality time with family members and not be zonked out, you know.  

Dr. Tonkin: Yeah.

Dr. Vaughn: You mentioned for pain, you know, I think of cannabis also having some other great benefits, maybe for anxiety or anorexia.  

Dr. Tonkin: Yeah.

Dr. Vaughn: Even one of the things that’s a common problem I have as you’ve I know experienced through your time in oncology is just the insomnia sometimes patients have, you know, with cancer, not only just diagnosis, but also just the treatment, it seems like patients have a hard time.  Maybe it’s the steroids we give, but – 

Dr. Tonkin: Exactly, lots of dexamethasone.

Dr. Vaughn: and then – the fatigue.

Dr. Tonkin: Yes.

Dr. Vaughn: But I’m sure cannabis has some data and those other categories. 

Dr. Tonkin: Yeah.  So, generally I try and use more CBD during the day, just because I don’t want people to be high, right. I mean sometimes patients will tolerate it, but that’s how I would start.  So that’s – the CBD during the day is great for the sort of what I call the anti-inflammatory type of bone pain that lots of patients have.  It’s very good for anxiety, and it’s very good sort of to help people just to chill so that, you know, because there’s a lot of anxiety with the diagnosis of cancer and they’re, you know, worried about what’s the doctor going to say cause I just had my CT or my MRI.  What’s my results going to be, so all of that sort of daily anxiety is a problem.  

When it comes to sleep, you need a THC based treatment because THC will tell the limbic system to quit worrying.  Just stop it, you know, just stop worrying.  So, you can often use a combination of THC and CBD and then they can sleep really well.  And then if you’ve slept well, then your whole day is better.  If you’re consistently not sleeping well then, your whole day is terrible, and your pain is worse.  If patients don’t find that CBD during the day is quite enough for their pain, you can give, you know, just start adding small amounts of THC.  

And interestingly, sometimes the THC will genuinely say, you know, they’ll say “my pain is better” and sometimes they’ll say again, because it affects the limbic system, the pain is the same, but it doesn’t bother me as much, and that’s what the limbic system is doing.  And that’s still a good result because that’s a quality of life thing, right?  But if you can get them down three notches, if they say my pain was 9 and now it’s 6, that’s the kind of thing that regular pain studies would say is worthwhile for a patient, a 30 percent reduction is very worthwhile for a patient.  So, any pain patient that I have, and not always cancer patients, but my arthritis patients, if they say well on average, it was an 8 and now it’s like a 5 you say yes, we’re doing something.  

And then you tweak the doses of it, because some are just not taking enough, either they’re – when you say take once a day, which it doesn’t really work that well once a day.  It needs to be taken at least twice a day.  Sometimes it’s three times, again depending on your metabolism.  So, sometimes, you know, they’re a bit scared to up the dose.  There is no dose with CBD.  

It’s what works and assuming you’re not finding something, like you’re getting a little too drowsy on it, cause sometimes CBD gives you a bit sort of couch potato effect or just a tiny bit of THC in it is beginning to follow that particular patient cause you can never get 100 percent pure CBD from a licensed producer because it costs so much money to get out the last half a percent of THC that they just don’t do it.  It’s just too expensive to do it.  

So, everything is at least 98 or 99 or something, but a tiny percentage of THC, which as you increase the CBD, for some patients it begins to bother them.  So, those are the sort of things that you say well just keep going up the dose until we come across a problem.

Dr. Vaughn: So if someone comes in and we’re assessing say for pain control, you’d recommend starting maybe twice a day oils, and again, is it, you know, I don’t even know, does it come in like a syringe or what – how much do you give or – 

Dr. Tonkin: The oils – in Canada what happened is they used to come with a sort of eye dropper, terribly inefficient way of doing it, as you’re trying to suck it up, you know, it’s ridiculous, I mean it’s completely inaccurate.  But so, some of them sort of come with more like a diabetic syringe.  So, now they’re just supposed to flip the bottle up and draw it.  And of course, now the stoppers aren’t very good, they kind of leak, so I mean, you know, in all these sort of issues of sort of Health Canada and telling the license – whatever.  

But the idea is you start with about quarter of a mil of something that’s about 25 milligrams per mil of CBD, and you do that twice a day, let’s say morning and lunch time, because if they’re going to take something at night to sleep, then by the time that CBD lunch time or maybe 2:00 in the afternoon has worn off, you’re going to be giving them something THC in the evening so they can sleep.  So, effectively, they’re getting three times a day, which is usually about right for people.  

Some people will say they take one dose in the morning, that’s good enough for them, that just really depends on them, but I would say most patients you start with like .25 of a mil.  It’s about 25 milligrams per mil, and then you do that twice a day and then you’re going to have something that is more like a 10/10, an equal THC/ CBD, and again, you start with 40 mil of that at night.  And then once you’ve got into that, then you start to increase.  And you say well when is your pain?  Later in the afternoon?  Okay, well increase the lunch time dose and you’ve got to .5, and then if that’s that enough, then you’re up to .5 in the morning, so then you grab – you sort of bring the two up to quite often 1.5 mils twice a day.  

And in the meantime, they may stay at a quarter of a mil at night, because at the beginning they might say well when I got up to go to the washroom, I was a bit wobbly.  They say well okay, stay there for four or five or six days, and if that wobbly feeling when they go to the bathroom in the night wears off and they’re not sleeping brilliantly, then they go up a little bit, .35 or .4 and then to .5.  Most patients at night will take between .25 of a mil to about a mil.  It’s occasionally somebody will take 1.25 mil, but not very often.  So, that’s sort of where you end up, about 3 mils of your 25 milligrams per mil of CBD.  And roughly I would say on average, about half a mil of your THC base at night to sleep.  

Your bigger problem is people who’ve got nerve pain, and as you know, there are many drugs you are given in chemotherapy that cause nerve damage, all the platinums and so on.  So, then the question is if we were to use cannabis earlier would we mitigate some of that?  And would it then enable you to give more of the platinum type drugs or any other drugs that cause neuropathy, would you be able to give more?  So, those are the sort of studies we haven’t done yet, and that’s really important.  What they have shown in animal studies is that CBD is good at preventing anthracycline type cardio toxicity.  

Well again, that’s super important, because you’re limited by how much anthracyclines you can give, lifetime anthracyclines, cause you might be giving in like in 2010 and then want to give it in 2015 and then you run out.  You can’t dare give it, because you know that extra dose, their rejection fraction can plummet, so who knows?  If we give CBD, at least in animal models, can we have a cardio protection from it?  So, there’s all these really interesting questions that we haven’t really got to.

Dr. Vaughn: You stole my thunder, cause I was going to bring up neuropathy.  You just hit that, cause that is probably the most frustrating side effect that patients feel and then providers feel because you’re right, you sometimes can’t even get maybe the dose that you need that’s therapeutic for treatments effects.  And it’s just so cumbersome on patients and you hate for their, you know, for something curable, their quality of life to be diminished because of the treatment, you know, we give them.

Dr. Tonkin: The only upside to that though is if they are somebody whose pharmacogenomics for that particular platinum drug is such that they’re a slow metabolizer, maybe they don’t need what you and I think is the average dose.  So, if we were doing their cyp enzymes, if that person is a slow metabolizer, maybe their real dose should be much less than that other person who can tolerate it much higher before they start to get neuropathy.  

So, the truth is we don’t really know what the correct dose is from patient to patient.  That’s actually something that yeah, we dose per meter squared, but you know that’s not really scientific.  We really should be having a situation where you can easily get cyp enzymes done for specific drugs, so you know, okay, Mrs. Smith, you need the low dose, because you are a slow metabolizer.  Mr. Jones, you need the high dose, because you are a fast metabolizer.  And we don’t do that.  And per meter squared is not scientific.  

Dr. Vaughn: Very archaic, and I tell my patients that.  We’re just basically, we’re back – 

Dr. Tonkin: Yeah, it’s like a shot in the dark.  

Dr. Vaughn: We can measure, you know, unmap the DNA of a tumor, we can get these wonderful radiology studies, PET scans, and yet we’re still using, you know, unit square as our dosing.

Dr. Tonkin: Yeah, so that’s one of the ways that I started to try and say to patients, don’t feel bad if I’m giving you a lower dose because your nerve damage may just be your slow metabolize and you actually are getting a perfect dose for you.  Cause otherwise the patients feel guilty, and the truth if I don’t know if that’s not true.

Dr. Vaughn: And you brought up another great point.  How do you think the future is going to be cause we’re going to need research on this?  How are we going to kind of integrate cannabis research with I guess what you’d say typical westernized medicine, where you kind of see how we can make sure this is therapeutic, it’s not harmful, it’s safe, dosing, how are we going to do this?

Dr. Tonkin: So, what makes it really complicated is that you and I have grown up in a medical system where you took a drug which may have come from a plant, like paclitaxel or docetaxel, comes from the yew tree, right?  But we synthesized it, so then we studied it and studied it and studied it and then we knew exactly what was the right dosing, what was the right schedule, everything.  The problem with plant-based medicine is that there are many things in it, so it’s not just THC and CBD.  There is THCA, which seems to be important, you know, for appetite, for cancer, for whatever.  There’s CBC, there’s CBG, there’s CBN, you know, there’s all these different subpopulations.  I mean within the plant the cannabis sativa plant, there’s over 100 cannabinoids.  

So, when we’re using a plant, even though you’re basically using THC and CBD, there are other cannabinoids that may be more important.  The question is, you know, you’ve got to extract the THCA or the CBG or whatever.  Then there are the terpenes.  And in Canada, Health Canada, said the terpenes have no medical benefits, but that’s actually not true.  During the day, you want to give a product that’s just got terpenes like linalool or limonene which will help keep you awake.  But at night, if you’re going to use something to help somebody sleep ,you want it to be like myrcene because it’s the terpenes that determine are you awake or asleep, not the cannabis.  

Then you’ve got flavonoids, which is literally the flavor.  And I don’t know that we know enough about those, but so the complicated question with cannabis is what cannabis am I giving you, because it’s not like saying I’m giving so many milligrams per meter squared or so many grams per meter squared, of a drug which I know all the risks and benefits of, right?  We’ve gone through phase one studies and everything has been done in that rigid way that we’re learned to believe in and understand.  And that’s what makes cannabis so difficult to study, because there are so many different preparations.  

And to go back to what you said, if you smoke it, if you vape it, if you use oil, if you use soft gels which they have now, and if you use edibles, all of those, just like in ordinary medicines, they will be absorbed differently.  So, if you give somebody an oral medication, it’s different than giving it subcutaneously or intramuscularly or intravenously.  So, cannabis is very difficult to study, and that’s what makes it hard.  

And the other problem is it’s difficult to patent.  The only thing you could patent as a licensed producer would be some process that you’ve developed, because otherwise how are you going to spend all this money on clinical trials and then everybody else can do what you’ve done?  And that’s why pharma companies work because they can patent something.  So, there’s a huge complication in studying it, not to say it’s not being done, because it is, there are massive numbers of studies.  

In fact, in 2017, the American Society of Science and Engineering published a metanalysis of over 10,000 papers that are being written about cannabis and said yes, we should be using it for pain, and yes, we can be using it for this, that and the other.  So, there have been very good metanalysis because the research, particularly in the laboratory, is phenomenal and then it’s gradually coming into the clinic.  There is one tumor for which there is pretty good evidence, and that’s GBM, you know, the glioblastoma multiforme.  

It’s a small study, but it’s been published in the British Journal of Cancer this year, and it shows that the – both groups got temozolomide and one group got this drug called Sativex, and Sativex comes from a company called GW Pharmaceuticals.  I hate to say it’s actually British, but it just happens to be.  And it’s a combination of THC and CBD, and you use it as an oral spray.  And it’s called an nabiximol because it’s not entirely plant based but it’s not entirely synthetic, so it’s a halfway house thing.  And they showed that the one-year survival in the group that got temozolomide and Sativex was 83 percent, and for those who got temozolomide alone, it was 44 percent.  

Dr. Vaughn: That is – I mean from an oncology standpoint, especially GBM, that is a great study.

Dr. Tonkin: Yes, the problem is it’s only about 30 patients.  So, although it’s been approved for emergency use in America, the FDA’s given it – because of course it’s an orphan drug, it’s an orphan disease, you know, because this is the current GBM, this is not first line, this is actually the current GBM.  It’s difficult.  They obviously need to do more studies, but this is actually now, this year, published in the British Journal of Cancer.  So, you can actually sort of look at it and say – and here in Canada it’s so expensive, Sativex, like $700 here or there.  

But I try and give them a one-to-one mixture, you know, of all the GBM’s to say I’ll do the best I can, but you’re never going to be able to afford because, you know, like in the states it’s almost never on a drug plan.  If you’re from the military or the police and very occasionally very good drug plans will cover it.  But the vast majority of patients it’s not covered.  And that becomes an issue because, as you know, oncology patients are often on disability, you know, income is really an issue, so if you add, you know, $100 or $200 a month, that becomes a real issue for patients.  You know, how can they afford it?

Dr. Vaughn: Where, as I was talking, where is the – you mentioned these studies.  Where for us as providers – where do we go for this information?  Is there a website, the Society of Cancer Clinicians?  Where would we get this information?  Cause that’s, of course, what we like is sort of medical journals to guide our decision-making.  How do we find it though?

Dr. Tonkin: So, if you just wanted to Google, you know, cannabis and nausea or cannabis and anorexia, it will give you, you know, Google is pretty good for that.  The Society of Cannabis Commission has actually got a very good training curriculum.  I shouldn’t blow my own horn, but I actually did the one on cancer.  And I basically said that really, we – virtual information is preclinical, and it’s actually – it’s fascinating and complicated because most of the information would suggest in the laboratory that cannabis will kill cancer cells, but not necessarily.  At nanomolar levels, you know, 10-9, it can actually promote cancer cell growth, and in some cell lines that don’t even have cannabis receptors, THC can promote growth because it can cause immune suppression.

So, why can’t it be we study, you know, in oncology, there’s always going to be some element of it that looks, you know, it’s going to go this way, it’s going to be a good thing, and then some other study comes out and says well actually there’s a negative thing going on here.  So, there’s a lot of – there’s a lot of work going on to try and, you know, tease out what are the, you know, where are we going to go with cannabis, even in the laboratory.  

So, that training curriculum is quite good, because they’ve got things on pain, they’ve got all sort of different training modules.  What we all did is we made PowerPoint presentations with audio, so if you become a Society of Cannabis Clincians member, which I think is $150 a year, then you have access to this whole training curriculum, which goes, you know, from A to Z really in terms of all the different things that you could learn about it.  But if you just want to do it simply, there’s a lot of things you can actually just Google.  Cannabis and something.  

Dr. Vaughn: I was kind of cruising through your website.  I think one of the movements which is kind of the goals I think of the society is to really begin, which I think has to be for the movement to really kind of build, is to start a process of educating, you know, medical students and healthcare professionals.

Dr. Tonkin: Yeah.

Dr. Vaughn: That’s great.  I think we need to start at that level too, to begin really maybe a course, you know.  I know going through medial school, gosh we do all these, you know, microbiology, immunology, but it would be great to have, you know, cannabis, you know course it. 

Dr. Tonkin: I think it’s really important, I mean some of the people in the Society of Cannabis Clinicians, they’re emergency room doctors, they’re all sort of physicians of all sorts of backgrounds.  I mean I would say, you know, of course, when we, and I’m sure it’s the same is true for you, they just told you that cannabis is a street drug.  And some of the patients come in like that and they – the first thing many patients will say to me is, “I don’t want to be high.”  And I say, “I don’t want you to be high either,” you know.  So, we often start off on that note.  

And then and the other aspect is that although I have over 100 different doctors who refer to me, some of my oncology colleagues from the cancer center where I work, they will refer to me and some will not, because some of them are believers that it can help the patients, and some are dead against it.  So, you know, there is a dichotomy amongst the medical profession.  More and more people, if they see their patients having success, will then send me more patients.  I mean it’s sort of obvious.  

I’ve got oncology colleagues who will send me patients cause they know I won’t do anything crazy and say oh, yeah, don’t do the chemotherapy, don’t do the radiation, do cannabis instead.  They know I’m not going to do that because I don’t think that’s a wise way to go.  But I do have some patients who would like me to say that.  And I say, no, really, that’s not a good idea.  I’m happy to help you through your treatment but what Dr. so and so at the cancer center is telling you, that’s actually the way to go, that’s your best bet.  I’ll help you if you’re worried about symptoms, but don’t substitute.  Because there really isn’t the data to substitute.  I mean even that GBM study of temozolomide plus or minus the cannabis, not the cannabis alone.

Dr. Vaughn: And something that I see every day, this happens, I have – and it’s generally an older patient comes in, you know, it could be either breast cancer or lung cancer, you name it, and usually the discussion on cannabis is brought up by their children, you know, so you have the children who are interested in it, maybe don’t have that stigma or fear that the older patients do, so you have this kind of turmoil going on with family members.  How do you approach that?  As you mentioned providers have, some providers have different stigmas, but sometimes it’s even within family members, you know, how do you bridge that?

Dr. Tonkin: I mean I think it’s a generational thing like that is quite common.  I mean I’ve seen patients where I will look – we have an electronic medical record, so I will look on that, and I’ll see that a particular patient has a very poor ejection fraction, so I’ll say I don’t want you to take THC because of the cannabis receptors in your heart, and you can see this elderly gentleman came with his grandson and he’s looking at me like well she’s an idiot.  And suddenly I could see it on his face.  This is before COVID, when we weren’t wearing masks.  And you could just see it on his expression like well she’s an idiot, I know more about cannabis than she does.  

And I will say well look, here’s the guide for you to take that, you know, you’re young and healthy, it’s all good, but for your grandfather I’m happy to give him CBD, but I think it would be inappropriate for me, you know, the do no harm thing that we have in medicine, to prescribe him something when his ejection fraction is 30 percent.  You know, when the normal is 50 and above.  I’m not saying it would harm his heart, but it has the potential.  

So, I’m always looking, you know, for these other medical things that are important for patients that I don’t know that a naturopathic doctor would necessarily have access to or look for.  But I’m able to, in my office, look at those electronic medical records.  So, that’s really important.  So, if there’s a generational thing, at the end of the day, it’s the patient’s decision.  

And you say I totally understand where your son or daughter is coming from, I’m not against it, and if you want to try some, you know, low-dose CBD and it’s not going to interfere with your treatment because you’re not on immune checkpoint inhibitor, you’re not on tamoxifen.  Let’s try it and just see how you go and come back and tell me how you feel.  Let’s not go crazy.  Let’s not have you smoking joints over here, there and everywhere.  

And you know, some older patients – I mean I’ve seen patients that will come in, and this is non-cancer patients, there’s a couple in there sort of, you know, professionals, and they’re both in their 50’s and they’ve been smoking cannabis every day for 30 years.  And you look at them and think, whoa, you would never think that.  But if they said they had a drink every night you wouldn’t think twice, so some people, you know, go medical because here in Canada you can put that on a T4 on your taxes at the end of the year and you’ll get some tax back.  Whereas, if you go recreational, I always say it’s like asking for your beer money back; that’s not happening.  

Dr. Vaughn: Not here, no, not here in the U.S.  They need all the tax money they can get.

Dr. Tonkin: Yeah, so but the difference is if you go to a store and buy it, that’s like going to buy your beer.  No one is going to give you your tax money back, but if you go medical, and I’ve written a prescription, all of those receipts you can put on your tax form.  Like if your physio isn’t covered or your chiropractor or your massage isn’t covered, they’re all your medical expenses and you will get some tax back.  

But you’ll never do that from a recreational store, and it takes people awhile to understand that.  So, you know, there are some benefits in Canada certainly for going medical, and I think you should, because I think it’s a drug, and I think I should be monitoring you on a drug, like any drug.  It’s like saying it’s okay to go and buy your opioids on the street corner.  No, we don’t think that is okay, right?

Dr. Vaughn: So true and, yeah, and it’s amazing, I mean I see just in the last three or four years, just here in Virginia, you know, the shift, as you know in the U.S. it’s different politics and some states it’s medicinal and recreational in some states.  Now here in Virginia it’s medicinal.  We’re starting to have more interest.  Patients are more interested, and it’s just so helpful to have doctors like yourself educate us, you know, and – 

Dr. Tonkin: So, let me ask you a question.  Within your practice, do you have somebody who you would call locally, a cannabis practitioner, that you could work with who would be providing the medical cannabis, or would you have to do it yourself?

Dr. Vaughn: That’s a great question.  In fact, I looked on – you have on your kind of Society of
Cannabis Clinicians like a locator.  I hit Virginia and was like well who’s the closest one to me, and I think it was in Richmond which is about 60 minutes away.  No, we don’t really have anyone.  It would be me, and again this is where I think we need to educate ourselves, you know, talking like with you is great and understanding, you know, how to prescribe it, dosing, how it helps, how do you monitor success.  You know, these kind of things I think we really – 

Dr. Tonkin: But how far away did you say the cannabis provider was from where your practice is?

Dr. Vaughn: In Richmond, Virginia, which is about 60 minutes.   

Dr. Tonkin: 60 minutes.  I mean if that’s not too far for your patients, wouldn’t it be nice, like let’s say you had an ENT specialist or an orthopedic specialist you liked, would it be worth having a conversation so that your practice would have access if somebody would say, I mean are you doing a lot of the tele-meds in the way we are here because of COVID?

Dr. Vaughn: Well, that’s actually what I just thought in my mind, like we could even do like a telemedicine conference, you know, bring that doctor in.   What you mentioned about, just kind of as we do have our own palliative care clinic and I’m just kind of thinking through this.  It would be great to start to implement this.  Maybe some guidance on dosing, you know, and some help.

Dr. Tonkin: Yes.

Dr. Vaughn: And then following it to see the benefits as we’re able to kind of lower opiates.

Dr. Tonkin: This physician in Richmond, would it be worth then coming to your practice one day a week?

Dr. Vaughn: Yeah.

Dr. Tonkin: And then all your cannabis interested patients could, you know, your palliative team, and you begin, you know, to develop something which would be very unique for your practice.  And then you wouldn’t have to worry so much – I don’t know what kind of physician that person is, whether they’re an internist or – 

Dr. Vaughn: That’s a good question.  I don’t know.  I just know that was the closest one that popped up, but and I think it would be something of interest, you know, to have someone – and yeah, like once a week, you know, to help us in our office, cause we have enough office space and maybe this is kind of where the movement is heading, you know.  It’s fascinating.

Dr. Tonkin: So, then you know, you can have the discussion with your patients, and you can say, well, you know, this person comes in once a week, you know, come back and discuss it with him, and then they’re working with you, they’d have access to your medical records, and you could be working just like you would with any other specialist.  As I say, we know in oncology you work with all sorts of people, you know, the respirologists, you work with the surgeons, you know, all that sort of stuff.  This would just be one more person.  And they may be willing to do it because they can see it’s a whole practice.  You know, you’ve obviously got a very big practice with all the oncologists, all the patients, the palliative area, and it would be very fascinating.

Dr. Vaughn: Oh yeah, and it would be great to see and then rewarding to see, kind of like you mentioned, the benefits we see.  And then I think when you see the benefits, you know, there’s more buy in.

Dr. Tonkin: Yeah, and so before you put them on the opioids, for example, you could say, okay, we’re getting to that stage, would you like to see the cannabis specialist in case we don’t need to put you on that?  Cause that’s what some patients will come to me and say, “Look, I’ve been offered opioids, I don’t really want them because I, you know, I don’t want the side effects, I want to try cannabis first.”

Dr. Vaughn: Right.  Well do you want to move to Fredericksburg?

Dr. Tonkin: Yeah.  

Dr. Vaughn: I’m so thankful for having you on.  This was very enlightening.

Dr. Tonkin: My pleasure.

Dr. Vaughn: Thank you so much.  I think this is going to be so informative for our patients to listen to this podcast and some of the providers that do, so thank you so much again, and this is hopefully a practice-changing phenomena.  I think cannabis has a lot of therapeutic benefits and I’m just so thankful for you educating us.  We’ll link this to our podcast so we can get a Society of Cannabis Clinicians.  Is that – am I saying it right?

Dr. Tonkin: Society of Cannabis Clinicians, that’s right.  That is a platform where they’re trying – not only cause I’m a board member, but I’m also there for an international member.  What they’re really trying to do is to focus on education, because everybody realizes as you’ve said already education is the thing for providers, for patients, for authorities to understand that we’re not trying to, you know, make everybody high on cannabis.  We’re really trying to use a wonderful drug in the best possible way to do no harm, but to help our patients.

Dr. Vaughn: Thank you again so much.  I appreciate it.  And enjoy the lovely summer up there.

Dr. Tonkin: Thank you.

Dr. Vaughn: It’s amazing. 

Dr. Vaughn: Thanks for listening to Cancer Shop Talk, Behind the Diagnosis.  Thank you again for joining us, Dr. Tonkin.  You can learn more about Dr. Tonkin’s work with Society of Cannabis Clinicians at  We are excited to continue our medical cannabis series next episode, From the Patient’s Perspective.  If you enjoy our show and want to know more, check out or leave us a review on iTunes.  

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