April 14, 2025 • 31 mins
The cannabis available today is dramatically stronger than what existed in previous decades, with THC levels climbing from 1% in 1970 to 25-30% in 2025, creating serious risks particularly for young people who don't understand appropriate dosing. Dr. Grover shares how cannabis has been deliberately bred for higher potency and how new extraction techniques have created products with astronomical THC levels, leading to dangerous situations like young people consuming 60 times a reasonable dose.
• Cannabis potency has increased from 1% THC in 1970 to 25-30% THC today through selective breeding
• Modern extraction techniques allow THC to be added back into products, creating concentrations as high as 45% and above
• A recreational dose of THC is between 2.5-15mg, but products often contain hundreds or thousands of milligrams
• "Greening out" or cannabis toxicity causes symptoms like confusion, vomiting, decreased consciousness, and anxiety
• Children are especially vulnerable to cannabis toxicity due to smaller body size
• Most cannabis toxicity cases resolve within 24 hours with supportive care
• Prevention requires understanding appropriate dosing and using cannabis judiciously
To contact Dr. Grover: ammadeeasy@fastmail.com
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Transcript
Episode Transcript
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Speaker 1 (00:00):
Welcome to the Addiction Medicine Made Easy
Podcast.
Hey there, I'm Dr Casey Grover,an addiction medicine doctor
based on California's CentralCoast.
(00:22):
For 14 years I worked in theemergency department seeing
countless patients strugglingwith addiction.
Now I'm on the other side ofthe fight, helping people
rebuild their lives when drugsand alcohol take control.
Thanks for tuning in.
Let's get started.
Today we are going to betalking about cannabis, and
(00:44):
we've covered cannabis on thispodcast many times.
But cannabis is changing andpeople are not aware of those
changes, particularly our youth,and it's leading to some
serious issues.
I lecture professionally ondrugs and alcohol all the time.
Let's quickly get us all up tospeed on cannabis.
(01:05):
Cannabis is a plant and itcontains multiple naturally
occurring chemicals.
One chemical,tetrahydrocannabinol, most often
referred to as THC, is thechemical in cannabis that gets
us high, and THC is what we'llbe focusing on for the next
little bit in this episode.
I've actually created a chartthat I use regularly when I
(01:29):
lecture that shows the potencyof plant cannabis over time.
In 1970, the cannabis was 1%THC and now, as of 2025, the
cannabis routinely is as high as25 to 30% THC.
People often ask me how did thishappen?
(01:50):
And it was actuallydeliberately done by cannabis
farmers to make the cannabisstronger.
I often explain this to peopleby referencing something a
little more mainstream so thatit's relatable.
More mainstream so that it'srelatable.
The analogy that I often giveis that people love watermelon
but don't really like having topick out the seeds.
(02:10):
So farmers wanted to make aseedless watermelon.
So what they did is, over time,farmers bred watermelon with
smaller seeds, with otherstrains of watermelon with
smaller seeds, and when thishappened, over multiple
generations of watermelon, theplant changes.
In other words, with farmingtechnology, farmers can change
(02:33):
how a plant grows.
So, by selecting watermelonstrains that had smaller and
smaller seeds, we now haveseedless watermelon.
And it's the same with cannabis.
Farmers bred stronger andstronger strains of cannabis and
we now have very strongcannabis.
Essentially, what it was isthat people like THC.
(02:55):
So farmers followed what peoplewanted and bred cannabis
strains with more THC over andover again, making the cannabis
stronger.
And furthermore, the cannabisindustry has innovated.
It has used chemistry toextract THC from the plant,
allowing THC to be put intomultiple different forms, such
(03:17):
as edibles and drinks, and weare now seeing the cannabis
industry actually put THC backinto plant-based cannabis to
increase the strength.
So one cannabis dispensary Iwent to had what are called
THC-infused joints, where thepercentage of THC in the
(03:39):
cannabis product was more like45% THC.
They actually took regularplant-based cannabis and then
supplemented that plant-basedcannabis with extra THC to make
it even stronger.
It's a little bit like in thealcohol industry they will add
in liquor to wine to make itstronger, like adding brandy to
(04:00):
wine to make it port.
However, the issue that I haveis we are now seeing cannabis
products with astronomicalamounts of THC and consumers are
not well informed.
The recreational dose of THC,what we might think of as a
(04:20):
single serving of THC, is notyet agreed upon.
It's somewhere between two anda half and 15 milligrams of THC.
But what we are seeing areproducts that are being sold
with drastically higher amountsof THC than that potential
single dose and, again,consumers really have no idea.
(04:43):
As I mentioned, I went to acannabis dispensary to see how
this stuff was sold and onepackage of four cannabis-infused
joints had 832 milligrams ofTHC in it.
That is potentially severalhundred times more THC than the
so-called recreational dose.
Now, the reason that this hasbeen on my mind is I heard from
(05:07):
one local school recently thatthey had some students get
pretty sick when they used THCbecause they used a lot and had
no idea how much the packagethey had contained compared to
how much they might be using interms of a recreational dose.
They bought a cannabis productthat had 3,000 milligrams of THC
(05:32):
in the package.
It was actually 10 individualservings of 300 milligrams and
again, the recreational dose, asin a single serving of cannabis
, is somewhere between two and ahalf and 15 milligrams of THC,
and this product was saying thata single serving was 300
(05:52):
milligrams of THC.
And these are high schoolstudents.
They had no idea how much was areasonable dose.
So they looked at the packageand it said it contained 10
servings.
So each of them took a serving,which again was the incredibly
high amount of 300 milligrams ofTHC.
(06:14):
If the recreational dose of THCis five milligrams, then the
package recommended that theytake 60 times what actually
might be that recreational dose.
Put another way, that is liketrying 60 beers instead of one
beer the first time you tryalcohol.
(06:37):
Fortunately, the students gotmedical attention, but they had
some serious adverse effectsfrom consuming that much
cannabis.
I go to schools very frequentlyand lecture about drugs and
alcohol, and when I'm going tobe going to schools.
Going forward, I'm going toreally focus on trying to give
(06:59):
the students an idea of how muchcannabis is reasonable for a
person to use, compared to whatis being sold, and I will likely
be sharing this case in ade-identified fashion as a part
of the regular lecture that Igive to students and also
parents, when I talk to themabout drugs and alcohol.
Now, if you didn't know, youcan overdose on cannabis.
(07:21):
It's often called greening outand, given what we talked about
now's as good a time as any fora refresher on what a cannabis
overdose looks like and how it'smanaged.
Fortunately, we covered thistopic on the podcast back in
2023.
So let's go back and listenright now to our previous
episode on cannabis overdose.
(07:42):
It was a great overview of thetopic.
Here we go.
This episode will be on thetopic of cannabis toxicity.
Now why are we covering thistopic?
Well, I was speaking to somehigh schoolers at the end of
last year about substance useand many of the kids had
(08:04):
questions about greening out.
I had not heard that termbefore, but when I asked the
students to describe what it was, they told me that it was what
happened when you smoked toomuch cannabis.
A few students had experiencedit and reported symptoms of
confusion, sleepiness andvomiting.
Reported symptoms of confusion,sleepiness and vomiting.
(08:28):
We covered cannabis-inducedpsychosis on this podcast in
episode 28, but what thesestudents were referencing
appeared to be somethingdifferent, so it was time to
figure this out.
As you can guess from listeningto previous episodes of this
podcast, the first place I wentto get more information on this
topic was PubMed and fortunately, I found a paper on the topic
(08:49):
pretty easily, and we will usethat paper as part of the
evidence-based backbone of thisepisode.
The title of the paper is AcuteCannabis Toxicity and it was
published in Clinical Toxicologyin 2019.
The lead author is MatthewNoble.
The authors begin with anintroduction section in which
(09:13):
they highlight a few pointsabout cannabis, and we will
review some of the key pointsthat they make.
The cannabis plants, cannabissativa and Cannabis indica,
contain over 60 cannabinoidcompounds, the most well-known
being THC and CBD.
As cannabis has been legalizedin more and more states here in
(09:37):
the United States, it is beingmore commonly used.
Furthermore, with legalizationof cannabis, more formulations
and preparations of cannabis areon the market, such as vape
liquids, gummies, pastries andhigh-potency oils, resins and
extracts.
Some of these products,including pastries like cookies
(10:00):
and brownies and gummies, arevery attractive to children,
which has resulted in increasedexposure of children, often
accidentally, to cannabis.
So this brings the authors tothe methodology of the paper,
which is an observational studyof the clinical effects
(10:21):
following acute cannabisexposures as reported to the
Oregon and Alaska Poison ControlCenter between December 2015
and April 2017.
There is quite a longmethodology section describing
how they were able to sortthrough, categorize and analyze
(10:41):
the poison control data.
But, bottom line, they reviewedall calls to this poison
control center when people wereexposed to cannabis and recorded
what happened to those people.
They excluded cannabinoidhyperemesis syndrome-related
calls, calls related to animalexposures and calls that
(11:02):
involved exposure to cannabisand exposure to another
substance or multiple substances, but they did include calls
that involved exposures tomultiple forms of cannabis at
the same time.
Okay, on to the results.
What did they find?
Well, they found 253 cases ofcalls related to cannabis
(11:24):
exposure.
These exposures to cannabisoccurred in people from 8 months
of age to 96 years of age andthe mean age was 25.
54% of exposures occurred inmales.
Most calls did not provide aquantitative amount of cannabis
(11:44):
consumed, but when there was anamount.
Reported exposures varied from2 mg to 1,000 mg of THC.
Most subjects were exposed to15 to 50 mg of THC and all of
the cases requiring hospitaladmission involved exposures to
(12:06):
15 mg of THC or more.
Now a quick aside For yourreference most recreational
cannabis doses are between 2.5mg and 15 mg of THC.
5 mg of THC has been proposedas a potential standard dose for
recreational use.
(12:26):
Back to the article.
The authors move on to describesome of the trends they
identified in the data.
First, they looked at acutecannabis exposures by age.
In kids under 12, edibles werethe most common exposure and
nearly all exposures in thisgroup were accidental.
(12:46):
Interestingly, kids under 12who were exposed to cannabis
were less likely to developtachycardia than adolescents or
adults.
In 90% of exposures, patientsof all ages exposed to cannabis
experienced adverse clinicaleffects.
Neurotoxicity was the mostcommon in all groups.
(13:09):
Children under 12 were morelikely to present with CNS
depression.
Adults were more likely topresent with CNS excitation and
adolescents had an equal splitof CNS excitation and CNS
depression.
Some examples of the CNSexcitation syndromes would
(13:29):
include paranoia, anxiety, panicattacks or hallucinations, and
some examples of the CNSdepression symptoms would
include ataxia, speechabnormalities, decreased loss of
consciousness and obtundation,and obviously, cns refers to the
central nervous system.
Most patients did not requireany specific treatment.
(13:50):
A small number of adults andadolescents required benzos for
CNS excitation and a smallnumber of adults and adolescents
required antiemetics for nauseaand vomiting.
Adults and adolescents requiredantiemetics for nausea and
vomiting.
Now, in terms of criticalillness, three patients in this
cohort were intubated as aresult of their exposure.
(14:10):
Two of these were infants andone was an adult, and all three
were exposed to high THCpreparations.
All developed severe CNSsedation and respiratory
depression, with one of theinfants having respiratory
failure.
All three were extubated within24 hours and recovered well.
(14:34):
The authors move on to lookingat how different preparations of
cannabis affected presentation.
When plant material wasconsumed, cns depression was
more common than CNS excitation.
When cannabis was smoked andinhaled, many subjects developed
.
Tachycardia and CNS excitationwas more common than CNS
(14:58):
depression.
When cannabis was consumed asan edible, cns depression.
When cannabis was consumed asan edible, tachycardia was less
common than when cannabis wassmoked and with edibles, cns
depression and excitation wereboth seen.
When cannabis was consumed as ahigh THC concentration resin
(15:19):
that's a solid there were higherrates of CNS excitation and
tachycardia as compared to otherroutes.
When cannabis was consumed as ahigh THC concentration liquid,
there were also higher rates ofCNS excitation and tachycardia
as compared to other routes.
And finally, high THCconcentration formulations of
(15:43):
cannabis were more associatedwith intubation than other forms
of cannabis.
Now the authors of the articlehave a lot of great tables in
the article, including a tabledetailing the clinical effects
of acute cannabis exposure byage and by cannabis product type
cannabis exposure by age and bycannabis product type.
(16:06):
They also have a chart thatdescribes in detail each of the
cases that were admitted to anICU after cannabis exposure.
To avoid this episode gettingtoo long, I won't review each
table in detail, but feel freeto check out the paper and take
a look for yourself.
However, there are a few pointsthat I wanted to call out from
these charts.
First, there were eight casesthat required ICU admission,
(16:30):
which was a little over 3% ofall the cases they reviewed.
There was one death, whichoccurred in a 70-year-old man,
and this accounted for 0.4% ofall the cases they reviewed.
He vaped a high THCconcentration liquid, then
developed a wide, complextachydysrhythmia and ST
(16:51):
elevation on EKG.
Autopsy revealed acute MI inthe setting of multivessel
coronary artery disease.
There was also a very widevariety of symptoms that people
experienced and that's reportedin Table 2 of the article.
They broke down symptoms intoseveral categories, with
(17:12):
specific symptoms listed in eachcategory.
Let's go through them to get asense of just how many different
symptoms people experiencedwith cannabis exposure.
Cns excitation Peopleexperienced anxiety, paranoia,
hallucinations, agitation,psychosis, seizure and tremors.
(17:32):
Cns depression Peopleexperienced decreased level of
consciousness, coma, syncope,confusion, ataxia and slurred
speech.
Other neurotoxicity Peopleexperienced confusion, dysphoria
, abnormal sensation, numbness,headache and lightheadedness.
Cardiac People experiencedpalpitations and chest pain.
(17:56):
Gi People experienced nausea,vomiting, diarrhea and abdominal
pain.
Respiratory People experiencedrespiratory depression, dyspnea
and cough.
And finally, some people alsoexperienced hyperthermia.
Here were the top fiveindividual symptoms from that
(18:17):
list that I just went through.
The number one symptom wasnausea and vomiting, which
occurred in 25% of patientsexposed to cannabis.
Number two was decreased levelof consciousness, which occurred
in 23% of patients exposed tocannabis.
Number three was anxiety,paranoia or panic, which
occurred in 22% of patientsexposed to cannabis.
(18:38):
Number four was palpitations,which occurred in 12% of people
exposed to cannabis.
And number five was confusion,which occurred in 10% of
patients exposed to cannabis.
So a wide variety of symptomswere experienced after exposure
to cannabis.
The authors move on to thediscussion section, and we will
(18:59):
hit the high points of thediscussion section.
The authors note thatneurotoxicity was common
following cannabis exposure,with variable presentations.
Cns depression was more commonin pediatric patients, and the
authors postulate that this maybe because the weight-based dose
of cannabis is greater inpediatric patients due to their
(19:21):
small size.
The authors follow this bynoting that there was an
increased risk in respiratorydepression and intubation when
concentrated THC products wereconsumed, particularly in
children.
The authors synthesize thesetwo points to highlight the
increased risk with cannabisexposure in children as compared
(19:42):
to adults, and that greaterefforts to reduce children's
risk of cannabis exposure shouldbe undertaken.
The authors also note that whenchildren were exposed to
cannabis, it was most oftenaccidental and the exposure to
cannabis most often came from acannabis product belonging to a
(20:02):
family member.
Okay, so that is the end of thefirst article.
I think the articlecorroborates what I expected to
be the case.
Kids are more vulnerable tocannabis toxicity.
Edibles are appealing to kidsand account for the majority of
exposures in kids, and high THCconcentration products have a
greater risk of toxicity in allage groups.
(20:24):
Now, this was obviously helpfulinformation, but I still felt
like I needed more informationon cannabis toxicity, so I went
back to PubMed and found asecond article, which was
published in StatPearls in 2022.
The title was CannabinoidToxicity and the lead author was
(20:44):
Brian Kelly.
This second article covers alot of the same topics as the
first article, so I will hit thehighlights.
The authors of this articleaddress the pathophysiology of
cannabis toxicity, which itsounds like has not been fully
worked out.
There are two cannabinoidreceptors in the body that are
(21:04):
part of the endocannabinoidsystem CB1 and CB2, both of
which are G-protein-linkedreceptors.
Cb1 receptors are mostlylocated in the brain, while CB2
receptors are mostly located inthe periphery.
Stimulation of CB1 receptors inthe brain leads to a modulation
(21:25):
of various neurotransmitters,including acetylcholine
glutamate, gaba, dopamine,norepinephrine and serotonin.
While the exact details havenot been worked out, excessive
stimulation of CB1 receptors bycannabis, such as with an
accidental ingestion or acuteheavy use, puts all of these
(21:48):
neurotransmitters out of balancedue to the effects of the CB1
receptors, and the cannabinoidsfound in natural cannabis are
only partial agonists at the CB1and CB2 receptors.
Synthetic cannabinoids are fullagonists at the CB1 and CB2
receptors and thus cause evenmore stimulation of CB1 in the
(22:12):
brain, which is why syntheticcannabinoids are more likely to
cause toxicity than naturalcannabis.
Moving on to the toxicokineticsof cannabis toxicity, the
authors note, quote the toxiceffects of cannabinoids are
secondary to overstimulation ofthe endocannabinoid system.
End quote.
(22:32):
The authors note up to fourhours after oral consumption.
The duration is also dependenton the route of use lasting two
to six hours after inhalationand lasting eight to 12 hours
(22:55):
after oral consumption.
The authors move on to thesigns and symptoms of cannabis
toxicity, which we coveredextensively in Article 1, so I
will just add one additionalnote from this section.
Cannabis toxicity can also, dueto the changes in
neurotransmitter function fromoverstimulation of the CB1
(23:15):
receptor in the brain, causesympathomimetic toxicity.
This can include, in severecases, rhabdomyolysis,
hyperthermia, seizures and renalfailure.
The authors conclude this secondarticle with a discussion of
the treatment of cannabistoxicity.
Quote.
Treatment of cannabinoidtoxicity is largely supportive
(23:39):
and focuses on symptomatic andsupportive care.
Most adult patients withcannabis toxicity improve on
their own with observation.
End quote.
For pediatric patients, theauthors note that there is a
higher risk of toxicity andobservation may need to be for
longer.
Also, social services may needto be involved to ensure that
(24:02):
the home environment is safe.
When there is severe cannabistoxicity, the authors recommend
benzodiazepines andantipsychotics to address
agitation, hallucinations andpsychosis.
Tachycardia can be managed withbenzodiazepines and IV fluids.
Considering that cannabistoxicity can cause
(24:23):
sympathomimetic toxicity,patients with vascular risk
factors may need to be evaluatedfor cardiac ischemia.
Seizures obviously would betreated with benzodiazepines.
The authors note that mostpatients can be observed for six
hours for improvement and orresolution of symptoms and
discharged home if improved.
For CNS, depression, confusion,seizures or persistently
(24:48):
abnormal vital signs, patientsmay need admission.
When edible products areconsumed, observation may need
to be longer due to the longerduration of effects from edibles
.
If patients do not clear orreturn to baseline, then
obviously further workup wouldbe needed, as cannabis toxicity
will resolve on its own once thecannabis is metabolized.
(25:10):
And that concludes our secondarticle on cannabis toxicity.
Now, before we wrap up thisepisode, I wanted to go back to
this term greening out that Iheard from the high school
students that I was talking to.
I searched the term on PubMedand found nothing.
So I went to a general internetsearch.
(25:30):
I found an article written by atreatment program called Boca
Recovery Center, entitled whatis Greening Out.
This is not a peer-reviewedarticle, so take the information
from the article with a grainof salt, but the article did
list several scientific articlesas references, so there's at
(25:51):
least some component ofevidence-based information here.
Let's dig in to this article.
The article begins with thesimple statement quote greening
(26:18):
out occurs when an individualmixed with other drugs or
alcohol.
The symptoms of greening outare described as pale skin,
nausea, vomiting, dizziness,disorientation, anxiety, panic
and, in severe cases,hallucinations.
As an aside, if those symptomssound familiar, it's because
(26:45):
they are the symptoms ofcannabis toxicity described in
the first article.
Moving on, this third articlenotes that greening out comes
from ingesting high amounts ofcannabis or THC-containing
products and that the risk ofgreening out increases with the
use of high THC-containingproducts.
Again consistent with the firstarticle we reviewed from PubMed
, this third article moves on tonote that regular cannabis use
(27:10):
will cause tolerance to cannabisand the risk of greening out
increases when a large amount ofcannabis is used in individuals
with low or zero tolerance.
The article moves on to a briefsection on what do you do if you
green out, and it's prettysimple.
The article counsels that mostepisodes of greening out will
(27:33):
resolve within 24 hours and thatintense symptoms should prompt
seeking medical attention.
The article recommends thatmild or moderate symptoms be
managed with rest, lying down,oral hydration and, if not too
nauseated, eating a meal.
Next, the article discusses howto prevent greening out, and
(27:54):
it's very simple Quote the bestway to prevent greening out is
to use cannabis productsjudiciously.
Do not consume too much.
End quote.
The article also points outthat it may take a while to feel
the effects of edible cannabis,so consuming multiple doses of
edible cannabis back-to-backshould be avoided.
(28:15):
The article concludes with someinformation for patients on
cannabis use disorder and thetreatment for cannabis use
disorder.
Okay, so we've done a prettygood review of this topic.
Cannabis use disorder.
Okay, so we've done a prettygood review of this topic.
Let's wrap up this episode oncannabis toxicity and greening
out with some take-home points.
Number one cannabis toxicity isthe result of overstimulation
(28:38):
of the endocannabinoid system,which causes disruption of the
normal function of multipleneurotransmitter systems in the
brain.
Number two functionally,cannabis toxicity can be thought
of as a cannabis overdose, asit is the result of consuming
enough cannabis to overstimulatethe endocannabinoid system.
(28:59):
For individuals who consumecannabis regularly and have
tolerance, it will take morecannabis to cause toxicity
compared to those who do nothave tolerance, such as children
.
3.
The top five symptoms ofcannabis toxicity reported in
one paper were nausea andvomiting, decreased level of
(29:21):
consciousness, anxiety, paranoiaor panic, palpitations and
confusion.
Number four as cannabis affectsmultiple systems of the body,
cannabis toxicity can manifestin multiple ways, affecting the
neurologic, cardiac,gastrointestinal and respiratory
(29:41):
systems.
Number five in children under12, most episodes of cannabis
toxicity are due to accidentalexposures to edibles.
6.
The risk of cannabis toxicityand the severity of cannabis
toxicity are increased inchildren due to their small body
size and when high THCconcentration products are used.
(30:06):
When high THC concentrationproducts are used.
7.
The onset and duration ofcannabis toxicity varies by
route of use, with the time toonset and duration after
consumption being longer withedible cannabis products.
8.
Treatment of cannabis toxicityis supportive, with nearly all
cases resolving within 24 hoursand most cases resolving within
(30:27):
24 hours and most casesresolving within six hours.
And number nine greening out isa term used to refer to
cannabis toxicity in thecannabis-using community.
Before we wrap up, a huge thankyou to the Montage Health
Foundation for backing mymission to create fun, engaging
(30:49):
education on addiction and ashout out to the nonprofit
Central Coast OverdosePrevention for teaming up with
me on this podcast.
Our partnership helps me getthe word out about how to treat
addiction and prevent overdosesTo those healthcare providers
out there treating patients withaddiction.
You're doing life-saving workand thank you for what you do
(31:11):
For everyone else tuning in.
Thank you for taking the timeto learn about addiction.
It's a fight we cannot winwithout awareness and action.
There's still so much we can doto improve how addiction is
treated.
Together we can make it happen.
Thanks for listening andremember treating addiction
saves lives.
Welcome to the Addiction Medicine Made Easy
Podcast.
Hey there, I'm Dr Casey Grover,an addiction medicine doctor
based on California's CentralCoast.
(00:22):
For 14 years I worked in theemergency department seeing
countless patients strugglingwith addiction.
Now I'm on the other side ofthe fight, helping people
rebuild their lives when drugsand alcohol take control.
Thanks for tuning in.
Let's get started.
Today we are going to betalking about cannabis, and
(00:44):
we've covered cannabis on thispodcast many times.
But cannabis is changing andpeople are not aware of those
changes, particularly our youth,and it's leading to some
serious issues.
I lecture professionally ondrugs and alcohol all the time.
Let's quickly get us all up tospeed on cannabis.
(01:05):
Cannabis is a plant and itcontains multiple naturally
occurring chemicals.
One chemical,tetrahydrocannabinol, most often
referred to as THC, is thechemical in cannabis that gets
us high, and THC is what we'llbe focusing on for the next
little bit in this episode.
I've actually created a chartthat I use regularly when I
(01:29):
lecture that shows the potencyof plant cannabis over time.
In 1970, the cannabis was 1%THC and now, as of 2025, the
cannabis routinely is as high as25 to 30% THC.
People often ask me how did thishappen?
(01:50):
And it was actuallydeliberately done by cannabis
farmers to make the cannabisstronger.
I often explain this to peopleby referencing something a
little more mainstream so thatit's relatable.
More mainstream so that it'srelatable.
The analogy that I often giveis that people love watermelon
but don't really like having topick out the seeds.
(02:10):
So farmers wanted to make aseedless watermelon.
So what they did is, over time,farmers bred watermelon with
smaller seeds, with otherstrains of watermelon with
smaller seeds, and when thishappened, over multiple
generations of watermelon, theplant changes.
In other words, with farmingtechnology, farmers can change
(02:33):
how a plant grows.
So, by selecting watermelonstrains that had smaller and
smaller seeds, we now haveseedless watermelon.
And it's the same with cannabis.
Farmers bred stronger andstronger strains of cannabis and
we now have very strongcannabis.
Essentially, what it was isthat people like THC.
(02:55):
So farmers followed what peoplewanted and bred cannabis
strains with more THC over andover again, making the cannabis
stronger.
And furthermore, the cannabisindustry has innovated.
It has used chemistry toextract THC from the plant,
allowing THC to be put intomultiple different forms, such
(03:17):
as edibles and drinks, and weare now seeing the cannabis
industry actually put THC backinto plant-based cannabis to
increase the strength.
So one cannabis dispensary Iwent to had what are called
THC-infused joints, where thepercentage of THC in the
(03:39):
cannabis product was more like45% THC.
They actually took regularplant-based cannabis and then
supplemented that plant-basedcannabis with extra THC to make
it even stronger.
It's a little bit like in thealcohol industry they will add
in liquor to wine to make itstronger, like adding brandy to
(04:00):
wine to make it port.
However, the issue that I haveis we are now seeing cannabis
products with astronomicalamounts of THC and consumers are
not well informed.
The recreational dose of THC,what we might think of as a
(04:20):
single serving of THC, is notyet agreed upon.
It's somewhere between two anda half and 15 milligrams of THC.
But what we are seeing areproducts that are being sold
with drastically higher amountsof THC than that potential
single dose and, again,consumers really have no idea.
(04:43):
As I mentioned, I went to acannabis dispensary to see how
this stuff was sold and onepackage of four cannabis-infused
joints had 832 milligrams ofTHC in it.
That is potentially severalhundred times more THC than the
so-called recreational dose.
Now, the reason that this hasbeen on my mind is I heard from
(05:07):
one local school recently thatthey had some students get
pretty sick when they used THCbecause they used a lot and had
no idea how much the packagethey had contained compared to
how much they might be using interms of a recreational dose.
They bought a cannabis productthat had 3,000 milligrams of THC
(05:32):
in the package.
It was actually 10 individualservings of 300 milligrams and
again, the recreational dose, asin a single serving of cannabis
, is somewhere between two and ahalf and 15 milligrams of THC,
and this product was saying thata single serving was 300
(05:52):
milligrams of THC.
And these are high schoolstudents.
They had no idea how much was areasonable dose.
So they looked at the packageand it said it contained 10
servings.
So each of them took a serving,which again was the incredibly
high amount of 300 milligrams ofTHC.
(06:14):
If the recreational dose of THCis five milligrams, then the
package recommended that theytake 60 times what actually
might be that recreational dose.
Put another way, that is liketrying 60 beers instead of one
beer the first time you tryalcohol.
(06:37):
Fortunately, the students gotmedical attention, but they had
some serious adverse effectsfrom consuming that much
cannabis.
I go to schools very frequentlyand lecture about drugs and
alcohol, and when I'm going tobe going to schools.
Going forward, I'm going toreally focus on trying to give
(06:59):
the students an idea of how muchcannabis is reasonable for a
person to use, compared to whatis being sold, and I will likely
be sharing this case in ade-identified fashion as a part
of the regular lecture that Igive to students and also
parents, when I talk to themabout drugs and alcohol.
Now, if you didn't know, youcan overdose on cannabis.
(07:21):
It's often called greening outand, given what we talked about
now's as good a time as any fora refresher on what a cannabis
overdose looks like and how it'smanaged.
Fortunately, we covered thistopic on the podcast back in
2023.
So let's go back and listenright now to our previous
episode on cannabis overdose.
(07:42):
It was a great overview of thetopic.
Here we go.
This episode will be on thetopic of cannabis toxicity.
Now why are we covering thistopic?
Well, I was speaking to somehigh schoolers at the end of
last year about substance useand many of the kids had
(08:04):
questions about greening out.
I had not heard that termbefore, but when I asked the
students to describe what it was, they told me that it was what
happened when you smoked toomuch cannabis.
A few students had experiencedit and reported symptoms of
confusion, sleepiness andvomiting.
Reported symptoms of confusion,sleepiness and vomiting.
(08:28):
We covered cannabis-inducedpsychosis on this podcast in
episode 28, but what thesestudents were referencing
appeared to be somethingdifferent, so it was time to
figure this out.
As you can guess from listeningto previous episodes of this
podcast, the first place I wentto get more information on this
topic was PubMed and fortunately, I found a paper on the topic
(08:49):
pretty easily, and we will usethat paper as part of the
evidence-based backbone of thisepisode.
The title of the paper is AcuteCannabis Toxicity and it was
published in Clinical Toxicologyin 2019.
The lead author is MatthewNoble.
The authors begin with anintroduction section in which
(09:13):
they highlight a few pointsabout cannabis, and we will
review some of the key pointsthat they make.
The cannabis plants, cannabissativa and Cannabis indica,
contain over 60 cannabinoidcompounds, the most well-known
being THC and CBD.
As cannabis has been legalizedin more and more states here in
(09:37):
the United States, it is beingmore commonly used.
Furthermore, with legalizationof cannabis, more formulations
and preparations of cannabis areon the market, such as vape
liquids, gummies, pastries andhigh-potency oils, resins and
extracts.
Some of these products,including pastries like cookies
(10:00):
and brownies and gummies, arevery attractive to children,
which has resulted in increasedexposure of children, often
accidentally, to cannabis.
So this brings the authors tothe methodology of the paper,
which is an observational studyof the clinical effects
(10:21):
following acute cannabisexposures as reported to the
Oregon and Alaska Poison ControlCenter between December 2015
and April 2017.
There is quite a longmethodology section describing
how they were able to sortthrough, categorize and analyze
(10:41):
the poison control data.
But, bottom line, they reviewedall calls to this poison
control center when people wereexposed to cannabis and recorded
what happened to those people.
They excluded cannabinoidhyperemesis syndrome-related
calls, calls related to animalexposures and calls that
(11:02):
involved exposure to cannabisand exposure to another
substance or multiple substances, but they did include calls
that involved exposures tomultiple forms of cannabis at
the same time.
Okay, on to the results.
What did they find?
Well, they found 253 cases ofcalls related to cannabis
(11:24):
exposure.
These exposures to cannabisoccurred in people from 8 months
of age to 96 years of age andthe mean age was 25.
54% of exposures occurred inmales.
Most calls did not provide aquantitative amount of cannabis
(11:44):
consumed, but when there was anamount.
Reported exposures varied from2 mg to 1,000 mg of THC.
Most subjects were exposed to15 to 50 mg of THC and all of
the cases requiring hospitaladmission involved exposures to
(12:06):
15 mg of THC or more.
Now a quick aside For yourreference most recreational
cannabis doses are between 2.5mg and 15 mg of THC.
5 mg of THC has been proposedas a potential standard dose for
recreational use.
(12:26):
Back to the article.
The authors move on to describesome of the trends they
identified in the data.
First, they looked at acutecannabis exposures by age.
In kids under 12, edibles werethe most common exposure and
nearly all exposures in thisgroup were accidental.
(12:46):
Interestingly, kids under 12who were exposed to cannabis
were less likely to developtachycardia than adolescents or
adults.
In 90% of exposures, patientsof all ages exposed to cannabis
experienced adverse clinicaleffects.
Neurotoxicity was the mostcommon in all groups.
(13:09):
Children under 12 were morelikely to present with CNS
depression.
Adults were more likely topresent with CNS excitation and
adolescents had an equal splitof CNS excitation and CNS
depression.
Some examples of the CNSexcitation syndromes would
(13:29):
include paranoia, anxiety, panicattacks or hallucinations, and
some examples of the CNSdepression symptoms would
include ataxia, speechabnormalities, decreased loss of
consciousness and obtundation,and obviously, cns refers to the
central nervous system.
Most patients did not requireany specific treatment.
(13:50):
A small number of adults andadolescents required benzos for
CNS excitation and a smallnumber of adults and adolescents
required antiemetics for nauseaand vomiting.
Adults and adolescents requiredantiemetics for nausea and
vomiting.
Now, in terms of criticalillness, three patients in this
cohort were intubated as aresult of their exposure.
(14:10):
Two of these were infants andone was an adult, and all three
were exposed to high THCpreparations.
All developed severe CNSsedation and respiratory
depression, with one of theinfants having respiratory
failure.
All three were extubated within24 hours and recovered well.
(14:34):
The authors move on to lookingat how different preparations of
cannabis affected presentation.
When plant material wasconsumed, cns depression was
more common than CNS excitation.
When cannabis was smoked andinhaled, many subjects developed
.
Tachycardia and CNS excitationwas more common than CNS
(14:58):
depression.
When cannabis was consumed asan edible, cns depression.
When cannabis was consumed asan edible, tachycardia was less
common than when cannabis wassmoked and with edibles, cns
depression and excitation wereboth seen.
When cannabis was consumed as ahigh THC concentration resin
(15:19):
that's a solid there were higherrates of CNS excitation and
tachycardia as compared to otherroutes.
When cannabis was consumed as ahigh THC concentration liquid,
there were also higher rates ofCNS excitation and tachycardia
as compared to other routes.
And finally, high THCconcentration formulations of
(15:43):
cannabis were more associatedwith intubation than other forms
of cannabis.
Now the authors of the articlehave a lot of great tables in
the article, including a tabledetailing the clinical effects
of acute cannabis exposure byage and by cannabis product type
cannabis exposure by age and bycannabis product type.
(16:06):
They also have a chart thatdescribes in detail each of the
cases that were admitted to anICU after cannabis exposure.
To avoid this episode gettingtoo long, I won't review each
table in detail, but feel freeto check out the paper and take
a look for yourself.
However, there are a few pointsthat I wanted to call out from
these charts.
First, there were eight casesthat required ICU admission,
(16:30):
which was a little over 3% ofall the cases they reviewed.
There was one death, whichoccurred in a 70-year-old man,
and this accounted for 0.4% ofall the cases they reviewed.
He vaped a high THCconcentration liquid, then
developed a wide, complextachydysrhythmia and ST
(16:51):
elevation on EKG.
Autopsy revealed acute MI inthe setting of multivessel
coronary artery disease.
There was also a very widevariety of symptoms that people
experienced and that's reportedin Table 2 of the article.
They broke down symptoms intoseveral categories, with
(17:12):
specific symptoms listed in eachcategory.
Let's go through them to get asense of just how many different
symptoms people experiencedwith cannabis exposure.
Cns excitation Peopleexperienced anxiety, paranoia,
hallucinations, agitation,psychosis, seizure and tremors.
(17:32):
Cns depression Peopleexperienced decreased level of
consciousness, coma, syncope,confusion, ataxia and slurred
speech.
Other neurotoxicity Peopleexperienced confusion, dysphoria
, abnormal sensation, numbness,headache and lightheadedness.
Cardiac People experiencedpalpitations and chest pain.
(17:56):
Gi People experienced nausea,vomiting, diarrhea and abdominal
pain.
Respiratory People experiencedrespiratory depression, dyspnea
and cough.
And finally, some people alsoexperienced hyperthermia.
Here were the top fiveindividual symptoms from that
(18:17):
list that I just went through.
The number one symptom wasnausea and vomiting, which
occurred in 25% of patientsexposed to cannabis.
Number two was decreased levelof consciousness, which occurred
in 23% of patients exposed tocannabis.
Number three was anxiety,paranoia or panic, which
occurred in 22% of patientsexposed to cannabis.
(18:38):
Number four was palpitations,which occurred in 12% of people
exposed to cannabis.
And number five was confusion,which occurred in 10% of
patients exposed to cannabis.
So a wide variety of symptomswere experienced after exposure
to cannabis.
The authors move on to thediscussion section, and we will
(18:59):
hit the high points of thediscussion section.
The authors note thatneurotoxicity was common
following cannabis exposure,with variable presentations.
Cns depression was more commonin pediatric patients, and the
authors postulate that this maybe because the weight-based dose
of cannabis is greater inpediatric patients due to their
(19:21):
small size.
The authors follow this bynoting that there was an
increased risk in respiratorydepression and intubation when
concentrated THC products wereconsumed, particularly in
children.
The authors synthesize thesetwo points to highlight the
increased risk with cannabisexposure in children as compared
(19:42):
to adults, and that greaterefforts to reduce children's
risk of cannabis exposure shouldbe undertaken.
The authors also note that whenchildren were exposed to
cannabis, it was most oftenaccidental and the exposure to
cannabis most often came from acannabis product belonging to a
(20:02):
family member.
Okay, so that is the end of thefirst article.
I think the articlecorroborates what I expected to
be the case.
Kids are more vulnerable tocannabis toxicity.
Edibles are appealing to kidsand account for the majority of
exposures in kids, and high THCconcentration products have a
greater risk of toxicity in allage groups.
(20:24):
Now, this was obviously helpfulinformation, but I still felt
like I needed more informationon cannabis toxicity, so I went
back to PubMed and found asecond article, which was
published in StatPearls in 2022.
The title was CannabinoidToxicity and the lead author was
(20:44):
Brian Kelly.
This second article covers alot of the same topics as the
first article, so I will hit thehighlights.
The authors of this articleaddress the pathophysiology of
cannabis toxicity, which itsounds like has not been fully
worked out.
There are two cannabinoidreceptors in the body that are
(21:04):
part of the endocannabinoidsystem CB1 and CB2, both of
which are G-protein-linkedreceptors.
Cb1 receptors are mostlylocated in the brain, while CB2
receptors are mostly located inthe periphery.
Stimulation of CB1 receptors inthe brain leads to a modulation
(21:25):
of various neurotransmitters,including acetylcholine
glutamate, gaba, dopamine,norepinephrine and serotonin.
While the exact details havenot been worked out, excessive
stimulation of CB1 receptors bycannabis, such as with an
accidental ingestion or acuteheavy use, puts all of these
(21:48):
neurotransmitters out of balancedue to the effects of the CB1
receptors, and the cannabinoidsfound in natural cannabis are
only partial agonists at the CB1and CB2 receptors.
Synthetic cannabinoids are fullagonists at the CB1 and CB2
receptors and thus cause evenmore stimulation of CB1 in the
(22:12):
brain, which is why syntheticcannabinoids are more likely to
cause toxicity than naturalcannabis.
Moving on to the toxicokineticsof cannabis toxicity, the
authors note, quote the toxiceffects of cannabinoids are
secondary to overstimulation ofthe endocannabinoid system.
End quote.
(22:32):
The authors note up to fourhours after oral consumption.
The duration is also dependenton the route of use lasting two
to six hours after inhalationand lasting eight to 12 hours
(22:55):
after oral consumption.
The authors move on to thesigns and symptoms of cannabis
toxicity, which we coveredextensively in Article 1, so I
will just add one additionalnote from this section.
Cannabis toxicity can also, dueto the changes in
neurotransmitter function fromoverstimulation of the CB1
(23:15):
receptor in the brain, causesympathomimetic toxicity.
This can include, in severecases, rhabdomyolysis,
hyperthermia, seizures and renalfailure.
The authors conclude this secondarticle with a discussion of
the treatment of cannabistoxicity.
Quote.
Treatment of cannabinoidtoxicity is largely supportive
(23:39):
and focuses on symptomatic andsupportive care.
Most adult patients withcannabis toxicity improve on
their own with observation.
End quote.
For pediatric patients, theauthors note that there is a
higher risk of toxicity andobservation may need to be for
longer.
Also, social services may needto be involved to ensure that
(24:02):
the home environment is safe.
When there is severe cannabistoxicity, the authors recommend
benzodiazepines andantipsychotics to address
agitation, hallucinations andpsychosis.
Tachycardia can be managed withbenzodiazepines and IV fluids.
Considering that cannabistoxicity can cause
(24:23):
sympathomimetic toxicity,patients with vascular risk
factors may need to be evaluatedfor cardiac ischemia.
Seizures obviously would betreated with benzodiazepines.
The authors note that mostpatients can be observed for six
hours for improvement and orresolution of symptoms and
discharged home if improved.
For CNS, depression, confusion,seizures or persistently
(24:48):
abnormal vital signs, patientsmay need admission.
When edible products areconsumed, observation may need
to be longer due to the longerduration of effects from edibles
.
If patients do not clear orreturn to baseline, then
obviously further workup wouldbe needed, as cannabis toxicity
will resolve on its own once thecannabis is metabolized.
(25:10):
And that concludes our secondarticle on cannabis toxicity.
Now, before we wrap up thisepisode, I wanted to go back to
this term greening out that Iheard from the high school
students that I was talking to.
I searched the term on PubMedand found nothing.
So I went to a general internetsearch.
(25:30):
I found an article written by atreatment program called Boca
Recovery Center, entitled whatis Greening Out.
This is not a peer-reviewedarticle, so take the information
from the article with a grainof salt, but the article did
list several scientific articlesas references, so there's at
(25:51):
least some component ofevidence-based information here.
Let's dig in to this article.
The article begins with thesimple statement quote greening
(26:18):
out occurs when an individualmixed with other drugs or
alcohol.
The symptoms of greening outare described as pale skin,
nausea, vomiting, dizziness,disorientation, anxiety, panic
and, in severe cases,hallucinations.
As an aside, if those symptomssound familiar, it's because
(26:45):
they are the symptoms ofcannabis toxicity described in
the first article.
Moving on, this third articlenotes that greening out comes
from ingesting high amounts ofcannabis or THC-containing
products and that the risk ofgreening out increases with the
use of high THC-containingproducts.
Again consistent with the firstarticle we reviewed from PubMed
, this third article moves on tonote that regular cannabis use
(27:10):
will cause tolerance to cannabisand the risk of greening out
increases when a large amount ofcannabis is used in individuals
with low or zero tolerance.
The article moves on to a briefsection on what do you do if you
green out, and it's prettysimple.
The article counsels that mostepisodes of greening out will
(27:33):
resolve within 24 hours and thatintense symptoms should prompt
seeking medical attention.
The article recommends thatmild or moderate symptoms be
managed with rest, lying down,oral hydration and, if not too
nauseated, eating a meal.
Next, the article discusses howto prevent greening out, and
(27:54):
it's very simple Quote the bestway to prevent greening out is
to use cannabis productsjudiciously.
Do not consume too much.
End quote.
The article also points outthat it may take a while to feel
the effects of edible cannabis,so consuming multiple doses of
edible cannabis back-to-backshould be avoided.
(28:15):
The article concludes with someinformation for patients on
cannabis use disorder and thetreatment for cannabis use
disorder.
Okay, so we've done a prettygood review of this topic.
Cannabis use disorder.
Okay, so we've done a prettygood review of this topic.
Let's wrap up this episode oncannabis toxicity and greening
out with some take-home points.
Number one cannabis toxicity isthe result of overstimulation
(28:38):
of the endocannabinoid system,which causes disruption of the
normal function of multipleneurotransmitter systems in the
brain.
Number two functionally,cannabis toxicity can be thought
of as a cannabis overdose, asit is the result of consuming
enough cannabis to overstimulatethe endocannabinoid system.
(28:59):
For individuals who consumecannabis regularly and have
tolerance, it will take morecannabis to cause toxicity
compared to those who do nothave tolerance, such as children
.
3.
The top five symptoms ofcannabis toxicity reported in
one paper were nausea andvomiting, decreased level of
(29:21):
consciousness, anxiety, paranoiaor panic, palpitations and
confusion.
Number four as cannabis affectsmultiple systems of the body,
cannabis toxicity can manifestin multiple ways, affecting the
neurologic, cardiac,gastrointestinal and respiratory
(29:41):
systems.
Number five in children under12, most episodes of cannabis
toxicity are due to accidentalexposures to edibles.
6.
The risk of cannabis toxicityand the severity of cannabis
toxicity are increased inchildren due to their small body
size and when high THCconcentration products are used.
(30:06):
When high THC concentrationproducts are used.
7.
The onset and duration ofcannabis toxicity varies by
route of use, with the time toonset and duration after
consumption being longer withedible cannabis products.
8.
Treatment of cannabis toxicityis supportive, with nearly all
cases resolving within 24 hoursand most cases resolving within
(30:27):
24 hours and most casesresolving within six hours.
And number nine greening out isa term used to refer to
cannabis toxicity in thecannabis-using community.
Before we wrap up, a huge thankyou to the Montage Health
Foundation for backing mymission to create fun, engaging
(30:49):
education on addiction and ashout out to the nonprofit
Central Coast OverdosePrevention for teaming up with
me on this podcast.
Our partnership helps me getthe word out about how to treat
addiction and prevent overdosesTo those healthcare providers
out there treating patients withaddiction.
You're doing life-saving workand thank you for what you do
(31:11):
For everyone else tuning in.
Thank you for taking the timeto learn about addiction.
It's a fight we cannot winwithout awareness and action.
There's still so much we can doto improve how addiction is
treated.
Together we can make it happen.
Thanks for listening andremember treating addiction
saves lives.
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