A Farmer Accidentally Injected Cow Antibiotic Into His Leg. This Is What Happened To His Organs.
JC is a 38 year old man, presenting to the emergency room, dizzy and nauseous.
Paramedics tell the admitting nurse that a bent syringe was found on the ground,
near where JC had collapsed.
JC was a cow farmer from Middle America. He was born and raised
on the farm where he lived with his wife, his kids, and his parents.
One afternoon in late winter, JC was getting ready to administer some medicine to his calves.
Dairy Calf Pneumonia, is an expensive and difficult to treat problem, and from his
experience being a lifetime cow farmer, he knew some of his herd would be at risk.
He gathered his cows and brought a young heifer, into a squeeze chute,
where the animal could still move around a bit,
while allowing the farmer some flexibility to administer an injection of antibiotic.
As he prepared the syringe for the dose,
he approached the heifer contained in the squeeze chute. One of the cows he walked
by was a “horned cow,” one that was about to give birth, maybe contributing to the
fact that it could be aggressive. And as JC was getting ready to inject the calf,
the horned cow rammed into him with such a force that he was immediately brought down to the floor.
JC tried to get up, but immediately, he felt dizzy. In the chaos,
he could feel a burning sensation radiating through his body. He realized that he had
accidentally jammed the top of his leg with the needle, and the syringe had plunged its
entire content of the antibiotic into his veins, because the needle was bent,
as he looked at it on the floor. When he stood up, his vision immediately turned dark.
As JC stumbled across the field, he collapsed on the ground again because he could no longer
see straight. He struggled to call for his wife, as she found him panicked,
dizzy and nauseous. 911 was called along with a neighbor and as help
arrived with an ambulance, JC was brought to the emergency room where we are now.
At examination, the medical team finds that JC has tachycardia. Tachy meaning fast and
cardia referring to heart rate. His heart rate was fast, but his blood pressure was low and his heart
rhythm was erratic. JC had told paramedics about the cow antibiotic he was about to administer.
He told them he was knocked over, and that the dose for an 850 pound cow (386 kg) was now in
his body. Doctors were presented with the bent syringe, that had almost no cow antibiotic left.
As they examine JC, they find that there was a mark where the needle poked through on his
leg. But seeing that the antibiotic was an animal medicine, and not a human one,
the medical team were unfamiliar with this, but they do have some clues as to what’s happening.
JC was working with Tilmicosin. If we remove the “For Humans” versus “For Animals” distinction,
antibiotics are grouped together in classes based on their chemical structure. These
classifications, tell us what they do to the bacteria, regardless of what species of animal
is receiving the medicine. Tilmicosin stops the internal machinery of bacteria. It prevents
that bacteria from producing vital structures it needs to function. The class of antibiotics, are called
macrolides, and in humans, you may have used one before, erythromycin as an ointment for
eye infections, or azithromycin, known in the United States as a Z-pack for a lung infection,
like pneumonia, kind of like how Tilmicosin is for Dairy Calf Pneumonia, bringing us back to JC.
As doctors in the emergency room read the medication label,
they get on the phone with the Poison Control Center.
The thing about macrolides, is that they have a side effect sometimes known to impact the heart. Usually
when this prescription is written, the human patient has already been checked for the
benefit of having a macrolide antibiotic for some kind of infection, and that benefit outweighs the risk of
those side effects. The problem is, tilmicosin isn’t a macrolide for humans. And even worse,
the 850 pound (386 kg) cow’s dose, became JC’s dose as the needle was shoved into his leg and
the syringe plunged the entire liquid volume in. JC got a dose several times more than an
equivalent human antibiotic, and knowing that these antibiotics can cause heart problems,
this should make sense, but which heart problem is this, and what typically happens here?
Well, the heart is a muscle. When it pumps, it contracts to push blood out and around the body,
and then it needs to relax to refill with more blood. Every single beat is a result of coordinating
the motions and the signals. And knowing that a heart beat happens on a timescale of seconds,
those signals need to be fast, meaning that those signals are going to be electrical,
not hormonal. And if it’s electrical, it means that it involves positive and negative charges.
Body electricity is precisely controlled by chemical ions that have those positive and
negative charges. When the heart wants to beat, a flood of positively charged sodium enters the
muscle cells to signal the start of a contraction. This signal is followed by an inflow of calcium,
which has an even stronger positive charge, and this sends a signal for the muscle cell
to release its own stores of calcium, and it’s this calcium that binds to the muscle
fibers to commit to the contraction. When it’s over, potassium rushes in to signal relaxation,
and the system resets itself before starting the process all over again.
The medical team noted he had tachycardia, so this electrical process was repeating itself in
a shorter amount of time than normal. But at the same time, his heart rhythm was erratic,
meaning that the electrical process was quickly falling out of sync. If his blood pressure is low,
it’s possible that something is preventing calcium from entering into the muscle cell
and binding to the fibers to help commit to the contraction of the heart beat,
bringing us back to the tilmicosin that JC accidentally injected into his leg.
When the medical team got contact with the poison control center, they were told,
Tilmicosin does appear to mostly just affect the heart in acute toxicity. And that it does that
by blocking calcium channels in heart muscle, a little different from how a toxic dose of human macrolides exert
their effect, which appear to block potassium going in to the heart muscle cells to signal relaxation.
JC had injected the antibiotic into a vein in his leg, which likely served the mega
dose directly to his heart, explaining why it acted immediately. The poison center also told
the medical team that Tilmicosin doesnt have an antidote, but they could try to give JC calcium.
The thing about toxicology studies, for situations and medicines like this, is that
we can’t get data on how to treat this kind of poisoning like in other branches of medicine,
because we can’t intentionally, knowingly, poison people and try antidotes to see if they work,
because you could end their life. At best, we can identify mechanistically,
how we could treat the next patient who comes in with this poisoning. We can also publish
how some of these poisonings are dealt with, but more things don’t get published than do.
And oftentimes, we’re more inclined to publish when treatments are a success,
but that still isn’t a guarantee that it will work again the next time, and in fact, it could be more
biased since the author was inclined to publish it because it was successful that one time.
Because Tilmicosin appears to block calcium channels in the heart, causing JC’s problem,
the medical team wanted to start to get the therapy ready. On the emergency room bed,
JC was notified that his family had arrived to the
emergency room to see him. He wanted to talk with them. But as he got up,
he suddenly collapsed. Emergency staff converge to his location to try to resuscitate him.
State investigators went to the farm. JC’s dad confirmed that the horned cow was likely
the culprit, because it had rammed him too when he walked by it later that day. Today,
Tilmicosin might still be used by farmers around the United States.
The maker of this medicine has implemented a training program that one must go through
before obtaining the medicine for their livestock, and they have also innovated
on the administration set to help prevent accidents like this from happening again.
At autopsy, the examiner determined that JC’s cause of death was respiratory failure due
to cardiac arrest, that happened because of an accidental, massive injection of cow antibiotic,
that’s absolutely not to be administered to humans, ever.
Thanks so much for watching. Take care of yourself. And be well.