Hi, Doctor Bernard here.
Don’t do this.
Just because Benadryl is over the counter doesn’t mean it can’t do bad things.
Even taking it as directed for allergies, often nets people a dullness and mental fog
that lasts in to the next day.
DON’T DO IT.
JC is a 21 year old woman, presenting to the emergency room, unconscious.
Her dad Scott, tells the admitting nurse that she had at least 3 seizures in the past hour.
The last one went on for more than 15 minutes, before he saw his daughter fall limp like
a rag doll.
You see, JC was a regular college student in 2020.
She just finished her finals, although, she had already moved back home earlier that spring,
because of pandemic.
This summertime break, was a good chance for her to pump up her internet following.
With TikTok being the favorite of all her friends, she was going to become internet
famous.
A small trend was growing over the weekend.
#BenadrylChallenge
This is going to be something big, she thought.
Back when she still had classes in person, she heard about Benadryl being able to “open
someone’s mind.”
Some of her friends tried it on the weekends.
She thought she had tried it during her freshman year, but couldn’t remember.
She couldn’t really remember anything from that year.
Haha TikTok meme she thought this time around, as she danced around on camera with 2 whole
bottles of Benadryl, before dumping them into her mouth.
And immediately after finishing both bottles, JC didn’t really feel anything.
She was going to be famous now.
She was going to get 10 million views.
“Allergy medicine go glug glug” she thought.
And what she didn’t realize is that the dose of both bottles combined, can be fatal.
As the hour passed, JC could feel a burning sensation at the base of her neck.
Her ceiling became like jello, wobbling around.
But ceilings are cringe.
Im floor gang now, she thought.
Always have been.
JC had never felt more relaxed, as she turned on some music.
She could hear people chanting her name over the speakers.
That’s the sound of being TikTok famous, she thought.
She tried recording more videos of her trip, but eventually she forgot what she was doing.
Her vision was blurry, but she didn’t need her eyes to see anymore.
There was a drum beating faster and faster in her chest.
Her mouth was like a desert, devoid of water, and her teeth were giant stones, grinding
each other down into sand.
JC looked at the clock.
12 hours had passed.
Her dad had come up to her and asked, “how many Benadryl did you drink?”
But she wasn’t sure if that was a hallucination or not.
She said she took 10 million, which is how many TikTok views she’d get, as she suffers
her first seizure.
In reality, no one was around.
Her dad hadn’t seen JC since hours before she took the Benadryl, as she falls unconscious
on the floor.
As Scott walks in on his daughter, he sees her suffer her third seizure.
While he called 911, and while the ambulance was on its way, JC’s seizure wouldn’t
stop.
But when paramedics arrived, she fell limp.
Her dad had no idea what happened as she arrives to the emergency room, where we are now.
At examination, JC was unresponsive.
She was flushed, but she didn’t have a fever.
Her heart rate was 180 beats per minute, about 3 times more than normal, but her blood pressure
was 70 over 40, about half of normal.
No one there had any idea that JC had taken a whole bottle of Benadryl, but there’s
a few clues as to what could be happening.
JC’s skin was red, but she wasn’t sweating.
Her pupils were dilated, and were minimally reactive to light.
Her mouth was dry, just like all her mucous membranes.
Her heart was beating fast.
All of this together, signals anticholinergic poisoning.
But what does that mean?
What is a cholinergic?
And what does it have to do with Benadryl?
Well, Benadryl is an allergy medicine.
Its chemical name is diphenhydramine.
Lots of people take it in the spring, when flowers are blooming.
Pollen and allergens cause people to sneeze.
To cough.
To have a runny and stuffed nose.
The body thinks these allergens are foreign objects that need to be removed.
What’s a good way to remove things?
Well you could dilate the blood vessels, and make them more leaky, in the hopes that the
allergens will leak out.
Benadryl stops this allergic reaction by stopping the signal for it, which is from a natural
chemical that’s made in your body, called histamine.
Hist from histidine, which is an amino acid, a building block of proteins in your body,
and amine referring to nitrogen which is a base word for amino acid.
But if Benadryl is just an over the counter allergy medicine, why did it cause JC to hallucinate?
It’s not like you’re stopping allergies in the brain!
And why is her heart beating so fast?
As the doctors keep examining her, they find she has a pulse, but her heart is beating
in a way, that if nothing is done about it, her heart will just shake in place, and won’t
be able to produce an actual contraction.
Doctors shock her in to a normal heart rhythm.
And after this happens, JC’s dad realizes his daughter had posted some TikTok videos
of her drinking 2 whole bottles of diphenhydramine.
He shows this to the doctors, and it tells them everything that they need to know.
Diphenhydramine inactivates histamine receptors.
It doesn’t stop the immune system from releasing histamine, it stops your body from interacting
with it.
When you take the dose on the instructions for allergies, this inactivates enough of
the histamine receptors, so that you don’t have a reaction.
But if someone takes too much, like lets say a 2 WHOLE BOTTLES, then that person is going
to have a lot of diphenhydramine floating around in the body, meaning it’s going to
interact with more than just histamine receptors.
But, what else would that be?
Well, if you’ve ever taken diphenhydramine, you know it can make you sleepy.
That’s why it’s branded as a sleep aid too.
Some parents give it to their kids before a flight so that the kid will sleep on the
plane and not cause a ruckus.
You shouldn’t do that to your kids.
But if you’ve ever taken it for sleep, you know you don’t wake up feeling great.
All of this means that Benadryl acts on the brain.
Which is clearly what it did to KC because as doctors transfer her into the intensive
care unit, she suffers her fourth seizure.
Nurses had to give medicine to stop the seizure, because it wouldn’t stop on its own.
The Benadryl deposits not just in her brain, but in all her organs because she took so
much of it.
This brings us to an idea called lipophilicty.
Lipo meaning fat and philic meaning affinity for.
Benadryl is lipophilic, meaning it dissolves in fat.
We know that water doesn’t mix well with oil, which is a fat.
Outside of the cells in the human body, there’s a bilipid layer, meaning your cells are coated
and defined by a layer of fat.
This would mean that a lot of Benadryl doesn’t want to be in the blood, because blood is
mostly made of water— it would want to be in the cells, so it can interact with that
bilipid layer.
And, more than 60% of the brain is made of fat, which is how Benadryl would get in.
Do you remember those histamine receptors?
Well they’re not just in the lungs and the skin to cause an allergic reaction.
They’re also in the brain.
And while histamine can cause blood vessels to dilate and become leaky elsewhere in the
body, in the brain it does different things.
It regulates sleep and wakefulness, so if Benadryl is there, cells don’t respond to
histamine anymore, so there’s no more regulation, and no more wakefulness.
That’s how it causes drowsiness.
Histamine’s also involved in cognition.
So if Benadryl is there to block it, then there’s less cognition.
Less cognition could mean more hallucinations, which sounds a lot like JC’s case.
Histamine also has anticonvulsant activity, so if Benadryl is there to inactivate it,
then there would be convulsant activity, explaining her seizures.
But she doesn’t just have a little bit of Benadryl in her body, she has 2 whole bottles of it.
But if it’s sitting in her organs, blocking all the histamine receptors, and there’s
still a lot of it floating around, what else would it block?
This brings us back to “anticholinergic poisoning.”
A “cholinergic” refers to the naturally occurring chemical called choline.
Which happens to have a similar structure to Benadryl.
One part of your nervous system signals for “rest and digest.”
This is mediated by the chemical acetylcholine, which is made inside your body.
And cholinergic receptors, take in acetylcholine to promote “rest and digest.”
But interestingly enough, since we have sequenced the entire human genome, we know what the
DNA in our body makes.
Nature likes to conserve things, and our genome tells us that almost half of this cholinergic
receptor, is just like the histamine receptor.
And because Benadryl isn’t too different in structure from choline, then it means having
a massive amount of Benadryl in the body, would cause it to bind to cholinergic receptors
too.
A lot of Benadryl means a lot of these cholinergic receptors don’t get acetylcholine anymore,
they get Benadryl instead, meaning, JC’s body can’t signal “rest and digest”
either.
Without a digest signal, her mouth becomes dry so no more saliva.
Her stomach muscles don’t move anymore.
She becomes flushed, but can’t sweat.
She can’t and hasn’t urinated since she took the whole bottle of Benadryl.
Her pupils become dilated.
And her heart doesn’t slow down, it speeds up to the point where it shakes in place and
doesn’t actually produce a real contraction.
In the intensive care unit, doctors give medicines to try and stabilize her heart rhythm.
Benadryl doesnt just stop the histamine signal, it doesn’t JUST stop the rest and digest
signal.
It also blocks sodium going in to heart muscle cells because the other part of its shape
happens to fit in those receptors in the heart too.
And because JC took a huge amount of it, there’s enough extra floating around to block anything
where it can fit.
Is there any way we could happen to pull it out of her organs?
Well, maybe.
But in most cases, this is treated by.. waiting it out.
Give medicines to stabilize her heart.
Give medicines to stop her seizures if they happen.
Ventilate her so that a machine breathes for her because she can’t do it on her own.
But maybe, there is a way we can exploit the chemical property of Benadryl to treat her.
Bringing us back to lipophilicity.
If Benadryl dissolves in fat, but not water, could we somehow infuse fat into her veins
in the hopes that it would pull out Benadryl from her organs?
At this thought, doctors infused the lipid emulsion used to feed critically ill patients,
intravenously.
JC’s heart rhythm didn’t change after the first infusion.
It’s still unstable.
Twenty minutes later, doctors infuse another bolus in, and then, her heart stabilizes,
and throughout the duration of her stay in the hospital, she never has another abnormal
heart rhythm.
In several case reports of this intravenous lipid emulsion therapy for various toxicities,
a positive inotropy was observed, meaning after infusion of fat emulsion, the heart
beats harder and stronger.
It’s possible that it could be the heart muscle changing energy source from glucose
to fatty acid from the emulsion.
But it could also be additional volume in the blood stretching the heart and causing
a rebound reflex.
Or it could just be because the toxicity has been reversed.
That’s the good part.
Sometimes, that bolus of fat can cause pancreatitis, cause the pancreas is supposed to help break
down fats, and it can also cause acute respiratory distress, that would be the bad part.
But in this case, JC turned out OK.
And on day 3 of hospitalization, she pulled out the tube that was down her throat.
Confused as to where she was, her dad explained to her everything that happened, as she realized
that the TikTok fame wasn’t worth the memes, especially since she felt a mental fog and
haze from the event, for several months afterwards.
Viral following is almost never worth it.
Because fast up is fast down.
Brightest stars burn out the fastest.
Thanks so much for watching, take care of yourself, and be well.