Podcast: Cannabis edibles
Transcript
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Kirsten Patrick: Cannabis edibles are now commercially available in Canada. Edibles include baked goods, candies, and beverages. We don't yet know if there will be an increase in the usage of these products, but it nevertheless is important for users and healthcare providers to be familiar with the health effects of cannabis edibles. I'm Dr. Kirsten Patrick, deputy editor for the Canadian Medical Association Journal. Today I'm speaking with the authors of a practice article on this topic. The article is published in CMAJ. Dr. Jonathan Zipursky and Dr. Nathan Stall are joining me today to discuss the issue. I've reached them in Toronto. Welcome.
Jonathan Zipursky: Thanks for having us.
Nathan Stall: Yes, thanks for having us today.
Kirsten Patrick: So I'm going to ask you to tell our listeners a bit about who you are. Jon, why don't you go first?
Jonathan Zipursky: Sure. So I'm Dr. Jon Zipursky. I'm internist and clinical pharmacologist at Sunnybrook Health Sciences Center.
Nathan Stall: I am Dr. Nathan Stall. I am internist and geriatrician at Mount Sinai Hospital in Toronto and I am also an associate editor for the Canadian Medical Association Journal.
Kirsten Patrick: Can you give us a rundown of how cannabis edibles are different from inhaled or oil based cannabis in terms of their makeup and effect?
Jonathan Zipursky: Sure. So cannabis edibles essentially refers to cannabis that's consumed in food preparations. Most commonly this refers to baked goods, candies, or beverages. So examples would be things like brownies, chocolate bars, gummy bears, or lollipops that that contain cannabis. The psychoactive component is essentially the same as you would find in inhaled cannabis or cannabis oils. And that's mainly THC. Because edibles are typically made by infusing that THC into fat soluble or lipid soluble products and then incorporating them into food products. I think there's also some really important pharmacologic differences between cannabis edibles and inhaled edibles. The main ones being that there's a delayed to sort of the peak onset of edibles. So edibles sort of reached their peak effect within within an hour or two of consumption, in contrast to inhaled cannabis that reaches its peak effect within approximately half an hour of inhalation. As well, the duration tends to be a little bit longer, the duration of effect tends to be a little bit longer for edibles. And those I think, are the two major differences.
Kirsten Patrick: So Nathan, how do you recommend people safely ingest cannabis? How can someone determine the proper amount to ingest and how long to wait before ingesting more?
Nathan Stall: Yeah, so that's, I mean, it's difficult as practitioners as healthcare practitioners to give recommendations about how to consume edibles. But I think that there are some principles some some safe principles that I think practitioners would be wise to discuss with patients who may be discussing consumption of edible cannabis. So the first is that now that cannabis is legal, and you will note that particularly in Canada, edible cannabis. Actually, the availability of legal products was not available until late 2019. But they are now commercially available. And so the point being there is that it'd be wise to use products that are actually regulated by the government. And that's because one, they have 10, a maximum dose in THC of 10 milligrams per packet. So some of the unregulated products can have much higher doses of THC. And that can obviously lead to intoxication or overdose. And the other thing is that dosing we know is regulated and not as variable. So some of the unregulated products, particularly when it's a baked good, the distribution of that THC amount in the product could actually be variable. So one part of the baked goods could be consumed, there may be a lower concentration of THC in there, as opposed to another part of that baked good. The other one is to follow sort of safe drug prescribing principles. So sort of the old adage start low and go slow, particularly for individuals who may be naive to cannabis and may be naive to edible cannabis. Jonathan has highlighted that even for people who are familiar with inhaled cannabis, there are very important pharmacological differences. So even those who are experienced cannabis users from using the form of inhalation, they can still run into difficulties because they are may not be familiar with the edible preparation. And that's particularly the the feature of edibles that it actually has a delayed onset to action, because you're ingesting rather than inhaling the product. So individuals who may not be aware of this may actually stack multiple doses on top of one another or something they're not used to when they consume inhaled cannabis. And I'd say finally, we have to recognize that the full sort of range of adverse health consequences about cannabis in general and especially for edible cannabis are not really known. And so individuals who may have underlying cardiac or psychiatric conditions should be especially wary and cautious about consuming these products. And also, one should be very cautious about combining cannabis with other psychoactive substances, including alcohol or other recreational drugs.
Kirsten Patrick: So it sounds like it might be easier to overdose with ingested cannabis then with inhaled cannabis. What are some of the signs and symptoms of overdose from edible cannabis?
Jonathan Zipursky: Sure, so the signs and symptoms associated with intoxication from edible cannabis are sometimes similar to the ones associated with inhaled cannabis. But there are some important differences. And certainly patients can experience gastrointestinal side effects, again, which are also common with inhaled preparations. Things like nausea and vomiting. But to some extent, I think major differences that I think patients should know and other health care providers should know intoxication with edible cannabis may lead to more significant sympathetic symptoms. And what I mean by that is cardiovascular symptoms like tachycardia, hypertension, or diaphoresis. And in addition, they may lead to more profound psychiatric symptoms and they can those can be things like anxiety, panic attacks, and even some psychotic symptoms or psychosis such as paranoia. And again, these these symptoms will differ depending on the sort of patient specific or occur on a case by case basis and may also differ amongst the age groups that use edible cannabis. I mean, the symptoms may be different for older patients as well as well as younger patients. So it tends to be patient specific.
Kirsten Patrick: Do you have any idea why the symptoms are different?
Jonathan Zipursky: Well, one specific reason may be that when cannabis is ingested, in order for THC to have sort of a, a psychoactive effect, it needs to be converted into a compound known as 11 hydroxy THC and when you inhale cannabis, less is actually converted to 11 hydroxy THC in comparison to when you ingest cannabis. Cannabis has to undergo what we call first pass metabolism in the liver in order for it to be converted to 11 hydroxy THC in a larger component actually gets converted when you consume or ingest cannabis than if you were to inhaled cannabis. So this sort of more psychoactive component, this 11 hydroxy, one would expect higher amounts of 11 hydroxy THC after ingesting cannabis compared to what after inhaling cannabis.
Kirsten Patrick: Nathan, you've been looking at studies of ER visits related to cannabis use. And there are some that have compared inhaled versus ingested cannabis. Can you tell us about these studies?
Nathan Stall: Yeah, so one of the largest studies and this was actually published last year in the Annals of Internal Medicine took place in Colorado, we know is a area that has had cannabis legalized for some time. And what they looked at was emergency department visits that were attributable to cannabis. And then they looked at the emergency department visits, both those that related to inhaled cannabis use and those that related to ingested cannabis use. And there's a couple interesting things in this study. So this study took place between 2012 and 2016 at a large urban academic hospital in Colorado. And so they looked at 10,000, nearly 10,000 emergency department visits with a visit attributable to cannabis use. And of those they were able when they did actually went through the charts, they found that about 25% of those visits were at least what they called partially attributable to cannabis. And what's interesting about it is they they look statewide, like what's the what's the proportion of cannabis sales that are for edibles, and that's actually less than 1%. But in the emergency department visits, they actually found the 10% of all cannabis related visits were for edible cannabis. So there seems to be you know, this this portion even though most of the visits again were for inhaled cannabis. When you compare that to the sales in the state, there was certainly a higher than expected presentation to the emergency department for edible related cannabis ingestion. So not only this disproportionate rate of visits to the emergency department is striking, but the other striking thing is that the reasons for presentations are also different. So what they found in the study was that individuals and this speaks to a little bit about the difference in pharmacology that John has highlighted, is that in for conditions like psychosis and anxiety, these symptoms were much more frequent in individuals consuming edible cannabis than those consuming inhalational cannabis. The same thing also goes for cardiovascular symptoms, and just overall for intoxication as well. So I think that's something to think about that that's quite important when we're talking about edible cannabis is that recognizing, you know, it's not just another route of taking the substance that there are actually quite important and as we heard from John, quite detailed differences in the pharmacology that are, as we're seeing here having differential adverse outcomes for people who are consuming cannabis.
Kirsten Patrick: In your article published in CMAJ, you make five main points and the last point is related to unintentional exposure in children, which you can imagine happening if edibles come in the form of gummy bears and other candy for example. What are some common ways or reasons that children end up ingesting cannabis?
Jonathan Zipursky: Children can be exposed to edible cannabis in a variety of ways. The most common reason that children are exposed is that they tend to mistake them for common fruit products. As you can imagine, these cannabis edibles are often times indistinguishable, both in look and in taste from their non-cannabis counterparts. In addition, they're often kept in similar locations in homes or in kitchens, to foods that don't contain cannabis. I think an important nuance is that sometimes children are unaware that an entire cookie or an entire chocolate bar, for example, would contain an extremely large dose of THC. Oftentimes, patients are instructed to take a portion of an edible or a small component of it as children would be unaware of this. I think another important point is that unregulated edible cannabis Nathan had previously referenced regulated edible cannabis. But unregulated edibles tend to be promoted in sort of colorful packaging, or they may be colorful or attractive themselves. And for these reasons, they may be very attractive to young children. This is one of many reasons why those who make regulated edibles have been instructed by the Canadian government to sell them in sort of plain packaging. And they're only allowed to contain a maximum dose of 10 milligrams of THC. And this is really an intentional Harm Reduction Strategy, in part aimed at preventing accidental consumption, or unintentional consumption in children.
Nathan Stall: The other thing I would add, John, is that, you know, because edibles take the form of products that seems so innocuous and benign, whether it's cookies, or gummy bears, they're often not stored in secure locations by individuals. And that's a problem. And I think this is actually made news several times. Unfortunately, as recently as last week, where a school in Eskasoni, Nova Scotia actually served, quite shockingly, a THC infused cake to schoolchildren. And so when these are not treated as drugs that have potential for harm, and are kept in sort of commonplace locations in people's homes, like pantries where they may store other baked goods, or other candies, children could get access to this in ways they may not have access to alcohol or other products that are stored in the home. And I think that that's something that we also highlighted in the article is that when children are in the house, these sorts of products should be stored in locked locations.
Kirsten Patrick: So what can happen if children do ingest cannabis and they ingest a far greater dose than they should have?
Jonathan Zipursky: So children are at increased risk. Accentuated and prolonged effects of edible cannabis are similar to some of them that both Nathan and I had described previously. But this really has to do with the fact that children are much smaller, they may have a smaller size and weight so they may be at risk of having severe or accentuated effects for a longer period of time. Sometimes, in fact, children will require admission to hospital after an unintentional or accidental exposure to edible cannabis. The Canadian pediatric surveillance program is currently running an ongoing surveillance study about cannabis and including edible cannabis. And from September to December of 2018, they identified 16 cases of edible exposures in children over 90% of the unintentional exposure were from edibles in this surveillance study. And shockingly of all, the unintentional edible exposures related to edibles that had been used or prescribed to parents and caregivers. And of these 16 edible exposures that they had identified 11 of those, actually 11 of those children actually required admission at observation hospital. I think that another important point is that children who consume edible cannabis may, in rare circumstances have extremely severe medical sequelae after ingesting the cannabis. In rare circumstances, there have been cases where children have had such significant respiratory suppression that they've required intubation. And again, in rare circumstances, they've even had seizures or had a coma. So I think, you know, our recommendations are what we suggest is really, there's no dose of cannabis that's safe for a child. And we would recommend that to both patients and healthcare providers that anytime a child is exposed to cannabis or ingest cannabis, parents should call their local or regional poison center and or consider presenting to medical attention.
Kirsten Patrick: That's very clear and concerning because the possibility of a child dying from respiratory depression that is undetected and coma is very real. Nathan, you're a geriatrician. Have you seen any increases in adverse outcomes with cannabis use or cannabis edibles in older adults?
Nathan Stall: As a geriatrician, just to bring it to the other end of the spectrum, we actually are starting now because since legalization Canada has been collecting data on this, and we know actually that, though, that although older adults, those over 65 are less likely than other age groups to consume cannabis, they're actually showing the most growth in cannabis usage. And, and when you look also at the most recent data regarding edible products, the most recent data we have that was published at the end of 2019 shows that edible products are actually increasing frequency. So among all cannabis users about 44% have tried or used edible products up from 41%. And I would say that while I think that they're also considering these pharmacological properties, and the fact that some older adults, particularly those that have cognitive impairment, or those that may be taking other psychoactive medications, this is another age group that probably hasn't fully been considered to the extent that needs to be in terms of what are the implications of cannabis legalization? And what are the implications, particularly about increased access to edible cannabis? Where there's really a dearth of data, and there's the potential for real adverse outcomes and adverse harms related to this age group.
Kirsten Patrick: What advice do you give patients who are wanting to try cannabis edibles for the first time?
Nathan Stall: Yeah, so we've talked a bit about this in terms of the principles of safe consumption that I think every person consuming cannabis ought to follow. And, and again, to reiterate, some of that relates to ensuring you're sticking to using regulated products. The following the principles of starting low and going slow, being aware of the unique pharmacological properties of edible cannabis, and in particular, the delayed onset to action. So I think all these things for healthcare practitioners now that edible cannabis is legal. And now that there is increased access and will be more increased access to edible cannabis. It's important that healthcare practitioners are aware of this information so that they can counsel their patients. The other the other point that I want to reiterate and I think this is something where in jurisdictions like Canada, where cannabis is legal is that there's a real opportunity for research because a lot of it is lacking, quite frankly. And I would I like to we we certainly don't know all the medical benefits of cannabis. And what we're talking about here is actually not cannabis for medical purposes. When we're talking about what we're talking about here is cannabis that's being used recreationally. But we also don't know the full range of potential adverse health consequences. And I think this is something that as as cannabis has become legal, it's become increasingly societally accepted. I think for many people, it's perceived as a benign and sort of innocuous substance and it should not be perceived that way. And there is really in the absence of data, we have to really be careful about the substance. So there are increasing numbers of reports in the medical literature of cannabis associated stroke and arrhythmias. We've talked about the study today talking about acute illness associate with cannabis use and the predilection for psychiatric and cardiovascular complications, particularly with edible cannabis. So patients who have underlying health conditions patients that are taking other psychoactive medications patients who consume other substances that are psychoactive whether it's alcohol or otherwise they really need to be cautious about consuming edible cannabis and I think the final thing to reiterate what we talked about with children is that these products should be respected they should be kept in stored and locked locations and one has to have an understanding of what's the concentration of the product that they'll be consuming and is this a product that may consume a larger dose of THC particularly for unregulated products where the intention of the manufacturer or the producer of this is for the consumer to divided into smaller portions so we highlight in the practice article that some cookies that can be purchased or baked goods that can be purchased may contain 100 milligrams of THC well if a typical intoxicating dose is about 10 milligrams you can imagine what consuming the entire 100 milligram THC cookie could result in with respect to toxicity so I think these sorts of principles of safe consumption and understanding the pharmacology and an understanding and respect for the fact that this is not necessarily an innocuous substance are things that frontline practitioners should be aware of so that they're able to have these conversations with their patients who are as we know going to be increasingly experimenting with cannabis and in particular edible cannabis.
Jonathan Zipursky: If i can add one last point and i think it's really important that patients as well know that it's important that they have open channels of communication with their healthcare providers and disclose their use of edible cannabis only because this might change a healthcare providers decision about whether to prescribe certain drugs or certain therapies in addition to some of the pharmacology that we've already described cannabis really needs to be thought of as a drug and there can be important drug drug interactions both pharmacokinetic and pharmacodynamic interactions and so I think it's really important that patients feel comfortable disclosing their use of edibles to their healthcare providers so that their whole healthcare team knows or helps them to do this safely.
Kirsten Patrick: Well thanks for helping CMAJ readers and listeners to get to grips with this really important topic and thanks for joining me today.
Jonathan Zipursky: Thank you very much for having us.
Nathan Stall: Yeah thanks for having us we really appreciate it.
Kirsten Patrick: I've been speaking with Dr. Jonathan Zipursky and Dr. Nathan Stall. Dr. Zipursky is an internist at Sunnybrook Health Sciences Center and Mount Sinai Hospital in Toronto. Dr. Stall is a geriatrician at Sinai Health System and a research fellow at Women's College Research Institute. Dr. Stall is also an associate editor for CMAJ but did not participate in the decision making on this article. To read the practice article they wrote along with their co-author Dr. Orly Bogler visit CMAJ.ca. Also don't forget to subscribe to CMAJ podcasts on soundcloud or a podcast app and let us know how we're doing by leaving a rating. I'm Dr Kirsten Patrick, deputy editor with CMAJ. Thank you for listening.