Hey Dr Bernard here. This throat numbing spray is medicine. There’s a label on the bottle required by law
telling you how to take it, and there’s a warning on that label, saying what can
happen if you take too much. Like this. That’s a lot of sprays. Just be careful when using it.
A Man Swallowed 1 Bottle Of Throat Numbing Spray
While Eating Spicy Food. This Is What Happened To His Brain.
RJ is a 21 year old man, presenting to the emergency room with shortness of breath, nausea,
and cyanosis. His face, especially his lips were a pale blue color.
A few hours earlier, RJ was eating spicy food with his friends. One of
his roommates had recently started working at a hot sauce store, and wanted to host a
little contest amongst friends to see who could handle the spiciest spice.
RJ was someone who just couldn’t be topped. He was that guy in the house who always had to argue
with everyone and he had to show everyone up. He looked online for ways to handle extreme spice and
came across throat numbing spray, usually used to treat sore throat and canker sores. He went
to the store, found a bottle, tried one spray in his mouth to understand what he was working with,
and he determined— it was time for him to outshine his roommates, again.
Later that week, on The Day Of The Spice,
the friends were ready to have some delicious chicken wings. One of the roommates dropped
out quick because they didnt like spicy foods, they just wanted to taste flavor
and enjoy what they ate. But everyone else knew that they wanted to show each other up.
RJ hid the throat numbing spray underneath his napkin, occasionally sneaking in a spray here and
there while everyone else was eating. At first, he would make it look like he was wiping his
mouth when really, he was pumping that spray. The sauces that they moved on to got spicier. Some of
the friends were having trouble handling it, but RJ wasn’t going to back down. He wasnt going to
admit that this was spicier than he could handle. He felt like the sprays were starting to not do
anything, and the bottle was kinda tall under the napkin, maybe looking kind of obvious. He started
to suspect that the others were catching on to him as he unscrewed the bottle of throat numbing
spray so he could take a couple of swigs. But accidentally, he spilled the bottle into his mouth
and some it started dripping down his chin. In an effort to not make it obvious to his friends that
he was adding a little help on the side to handle the spice, he swallowed what was in his mouth.
RJ felt like his tongue was too big for his mouth. He could bite down on it and feel nothing. But
then he felt like his head was pounding. He could feel his heart beating in his neck as the air
coming out of his nose felt warmer than normal. One of the friends suspected something was wrong,
but they just didnt know what. He called RJ out and said, “Check out Papa Smurf over here” as
everyone noticed that RJ was blue in in the face. The throat numbing spray that he was
hiding was blue and he some of it was dripping off his chin. Panicked, thinking that everyone
knew what he was doing, RJ got up and quickly ran to the bathroom. But the moment he got up,
his field of vision turned dark. In the bathroom now, RJ was gasping for air. The
sounds in his ears couldn’t make any sense to him. One of the friends found the empty bottle
of throat numbing spray on RJ’s seat and realized what he had been doing. At first,
they found it hilarious. But when they looked closer at the bottle, they saw a warning to
seek immediate medical attention if blue colored skin develops during the use of this product. And
when RJ wouldn’t come out of the bathroom, they went in and saw his complexion an even paler blue
color. He was laying down on the floor, as they drive him to the emergency room where we are now.
Immediately, medical staff notice RJ’s cyanosis. Cyan from Ancient Greek referring
to the blue-green color and -osis meaning abnormal state. His face his lips, and his nail beds were
a bluish green color, indicating that there’s some lack of oxygen in RJ’s blood. They quickly
give him supplemental oxygen in order to remedy this. This throat numbing spray that RJ dumped
into his mouth is the same cyan color that his complexion is now, but, he spilled some of it
on to the skin of his face. It’s possible that some of the food coloring dyed his lips blue,
and that nothing at all is wrong with RJ meaning that maybe that oxygen isn’t going to do anything.
But as the time passes, it becomes clear that that oxygen isn’t going to do anything, but there’s
definitely something wrong. The oxygen doesn’t change the color of his complexion. Even worse,
he’s starting to become unresponsive, meaning that something is happening to his brain. When he
presented to the emergency room, they had put a pulse oximeter on his finger in order to
check oxygen saturation in his blood, that is the measure of how much his hemoglobin, that is the
protein in red blood cells that’s supposed to carry oxygen, is actually carrying oxygen. The
pulse oximeter shines a light on one end, and measures how much remaining light is
received on the opposite end to determine that percentage of oxygen absorbed by his red blood
cells. If they’ve been giving him oxygen, but he’s still blue, and the pulse oximeter
is saying that his hemoglobin isn’t carrying a lot of oxygen, and it’s clear now that his
brain is shutting down because it’s not getting enough oxygen, then what could be happening?
The medical team draws some blood from RJ’s arteries to test. And finds that huge amounts
of oxygen are in his blood. This should make sense. The oxygen that RJ is receiving is going
into his lungs, and put into the blood that’s coming from his heart. This oxygenated blood
then flows back to the heart where it’s pumped out to the rest of the body through the arteries,
which is where the medical team drew his blood. But if all of this is happening,
WHY is the pulse oximeter saying that RJ’s oxygen saturation is
low? And more importantly, why is he still blue and gasping for air?
Red blood cells are supposed to carry oxygen. They do this through a protein called hemoglobin,
which contains iron, and that’s what carries the oxygen. If the arterial blood that the
medical team collected from RJ shows that he has a large pressure of oxygen in his blood,
but the pulse oximeter is showing there isn’t much oxygen attached to his blood cells,
then it means that oxygen is in the blood, but for some reason his red blood cells can’t hold
on to that oxygen. And if iron in hemoglobin is supposed to carry that oxygen in normal function,
then this is where RJ’s problem is. This methemoglobinemia, met from meta in this
case referring to between, or a kind of altered state while retaining some structure
and characteristic of the original but being different in a very important aspect of function,
hemoglobin being the protein that holds on to oxygen, and -emia meaning presence in
blood. An altered hemoglobin presence in blood, but why is this happening?
The active ingredient in the spray that RJ used is benzocaine. The -caine suffix in the name denotes
a local anesthetic, meaning that it’s a medicine that’s supposed to numb the area to where it’s
applied. The nerves rely on sending electrical signals to the brain for the sensation of pain,
but benzocaine generally dampens that electrical signal so that the pain sensation isn’t sent.
This happens at regular doses, which for this throat numbing spray is one pump,
that’s spit out after leaving it in the mouth for a minute. But that’s not even close to the
amount that RJ took and put inside his body. And at doses like the one he took,
the chemical structure of benzocaine explains everything happening to RJ.
We’re familiar with metallic iron. When metals are used for normal function in the human body,
they’re not in their solid metal form, they’re ions,
meaning that they are electrically charged. The problem with iron,
is that it can have different electrical charges. This is why it’s special, but why does it do that?
Electrical charges on elements are because of changes in how many electrons are on the atom.
If there’s more electrons than normal, then that ion is negative. If there’s less electrons than
normal, then that ion is positive. Normal is dictated by the number of protons in the atom,
which are positively charged, so when the number of electrons equals the number of protons,
the atom isn’t charged at all. Nature has a tendency towards stability, in this case referring
to less energy. Electrons on atoms are laid out in energy levels. The larger the element, the
more energy it has, and that means it can become more reactive, because it can release, or wants
to release that energy and react with something to become more stable. The reason why iron is special
is because of exactly how many protons it has, and how energy levels are arranged in nature.
The layout of the periodic table of elements tells us the energy
levels of every single element. Each of the columns on the left and right denote groups,
and members of each group tend to exhibit some similarities with each other, while going along a
row denotes an incremental increase in protons, and elements will tend to behave differently
as you count up. Iron is the first of its group, but the row that it’s in is called the Transition
Metals. As we count upwards on Iron’s energy levels, nature says we can remove 2 electrons,
and iron can be stable, because removing those 2 electrons eliminates its highest energy level,
giving some stability to the ion. The interesting thing about iron 2+ in hemoglobin, is that it’s
responsible for carrying oxygen and delivering it to tissues and organs. However, the reason it can
bind oxygen is because it still has some degree of instability, and the electron placement of Iron
2+ tells us that further stability can be achieved when one more electron is removed,
because at the remaining highest energy level, the presence of a 6th electron in that energy orbital,
as is the case for Iron 2+, provides some opposition. We see this play out in daily life.
When rust forms, it’s iron coming into contact with oxygen and water, that pulls away electrons
from the metal and forms hydrated Iron 3 oxide. While Iron 3+ is more stable— in hemoglobin,
its presence means that that hemoglobin can no longer carry oxygen. Actually,
while regular hemoglobin is holding on to oxygen, the Iron 2 becomes Iron 3,
plus oxygen, and becomes Iron 2 again when it lets go of the oxygen. But as this methemoglobin
circulates around in RJ’s body, none of his organs can get oxygen because his blood cells
cant transport it in, as they start to shut down. His brain is starving of oxygen as he becomes
unconscious and it starts to shut down. But what does this have to do with benzocaine spray?
RJ sprayed too much, when he was still only spraying. The oral mucosa is highly vascularized,
meaning that lots of blood is flowing through. So he was getting benzocaine
absorbing into his blood here, and he was swallowing the sprays. But then,
he accidentally dumped the bottle in his mouth and swallowed even more. The benzocaine
spray then went into his stomach, absorbed from his small intestines into his liver,
where it was metabolized, or broken down, adding even more to the amount in his body.
One goal of liver metabolism is to make the chemical more water soluble meaning it can
dissolve in water, so it can concentrate in the urine and be eliminated from the body. This is
called making the chemical more hydrophilic. Hydro meaning water and philic meaning affinity for.
Water is made of oxygen and hydrogen, so adding oxygens to a chemical in this way, should increase
hydrophilicity, but, for benzocaine, doing this brings us back to the problem of stability.
We already established that electrons play a role in the stability of iron. When benzocaine
is metabolized, one of the resulting chemicals that happens to be hydrophilic, is a phenyl
hydroxyl amine. The electrons in this molecule are delocalized, meaning that they are distributed
among the structure, a little different from how elemental iron places them on energy levels.
Phenyl hydroxyl amine is hydrophilic, but it isn’t stable. It has an extra electron it wants to get
rid of to establish stability, therefore making it reactive. The human body has an abundance of
oxygen, so Phenyl hydroxyl amine gives its extra electron to oxygen and becomes nitrosobenzene,
while that receiving oxygen becomes superoxide, an oxygen with an extra electron. Superoxide is
reactive meaning it isn’t stable, so the body tries to handle this by reacting it with water,
but that creates hydrogen peroxide, which is an unstable chemical that takes electrons to become stable.
And if hydrogen peroxide is in the blood, an easy target to take electrons from, is Iron 2+ in hemoglobin.
This brings us to an idea called equilibrium. The nitrosobenzene from Phenyl hydroxyl amine
produced by the metabolism of benzocaine, is also unstable. It pulls electrons from elsewhere in the
body to become phenyl hydroxyl amine again. The two of these species, exist together,
endlessly cycling between one another, shuffling electrons around and creating massive amounts
of superoxide, and exerting heavy oxidant stress, reacting with iron 2+ in the blood,
turning significant parts of RJ’s hemoglobin into methemoglobin, incapable of transporting
any oxygen throughout the body, despite the direct administration of oxygen into his lungs.
This mechanism of oxidant attack in the blood happens with several different chemicals,
when they are put in to the body, all of which result in methemoglobinemia,
and can cause all the organs to shut down due to lack of oxygen.
In the hospital, the medical team already picked up on what was happening. They may
not have known that benzocaine was the cause at first, but the clues to methemoglobinemia
were all there. RJ’s blue face and lips and gasping for air. The low oxygen saturation
on pulse oximetry when supplemental oxygen was being given. The high oxygen pressure
during the blood test, and the chocolate appearance of the blood when it was drawn,
not being a bright red like normal. If RJ’s problem is electrons being
extracted from the iron in his blood, how is one supposed to replace those electrons?
This brings us back to equilibrium. Methemoglobin exists in normal function, it’s just that our
bodies can easily add the extra electron to Iron 3+ to make it Iron 2+, so there isn’t normally
a lot of methemoglobin. But when an endless cycling of phenyl hydroxyl amine from a huge
ingestion of benzocaine keeps creating stress, the body’s mechanism to reduce Iron 3 is quickly
overwhelmed. However, there’s another approach the body can use, it just needs an intermediate to
help carry the electrons around. And ironically, as RJ’s skin and lips are blue, the antidote that
will replace the electrons in the iron in his blood, is a dye called methylene blue.
The medical team noted RJ’s methemoglobinemia, but it was one of the friends who showed staff
the bottle of benzocaine throat numbing spray that they thought he drank. The medication label
has a clear warning on the back to not misuse it. And all of this prompted the medical team
to start methylene blue, when they gathered the information they needed to know. And very quickly,
an improvement was found in RJ’s cyanosis. But more time was needed to observe him in
the hospital, because while methylene blue was indicated in his case because of how
severe his methemoglobinemia was, it isn’t without risk, and RJ took enough benzocaine,
that just one dose of methylene blue probably isn’t going to be enough.
Misusing throat numbing spray isn’t new. It’s not hard to find videos of people
doing it. Not all throat numbing sprays are made the same. Some have different
active ingredients that aren’t benzocaine, and thus, may not cause methemoglobinemia,
although they could cause other problems when misused. Benzocaine is also found in some cough drops,
and that has the same methemoglobinemia warning, which if you look, the US FDA has issued warnings
several times throughout the years about this. Also because benzocaine is a topical anesthetic,
there could be misuse in other sensitive parts of the body. There is no limit to what you can
choose to imagine here. Medical literature has documented risks with benzocaine spray,
sometimes during endoscopic procedures, and I remember a time in the mid 2010’s when the
spray was something hard to get in the hospital in part because of this problem of methemoglobinemia.
Throat numbing spray can be helpful when you have the common ailments of cold, flu, sore throat,
canker sores, not to eat more spicy foods than your friends. Please be careful because this
dosage form can be easy to want to take more, the directions for use are right on the label.
Last point, the antidote methylene blue is used here because RJ had an active poisoning. If you
don’t have an acute illness, or a diagnosed pathological condition,
if you don’t need to put it in your body, don’t put it in your body. As RJ was monitored in the
hospital he needed a bit more methylene blue. But finally as the days passed
and he was watched closely by the medical team, he was discharged from the hospital
as he learned a lesson about not needing to argue and show up his friends all the time,
and about not misusing throat numbing spray as he was able to make a full recovery.
Thanks so much for watching. Take care of yourself. And be well.