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BLOG: Keep your medications away from your pets
“Can I have a refill on my Armour Thyroid?” one of my patients asked.
“But the electronic medical health records show that you had a refill a few day ago,” I replied.
That was the conversation that took place a couple of years ago in my clinic.
Armour Thyroid (thyroid tablets, USP, Allergan) is used for the treatment of hypothyroidism.
As I have done on a needed basis, and while this blog is mostly not about discussions of in-depth scientific literature, I have dedicated a few posts a year to discuss scientific issues that are not covered by the mainstream medical literature, such as reminders to insulin pump users to change the pump’s clocks for daylight saving time. In this post, I will discuss an issue that I believe is overlooked in the human medical literature.
“The dog ate my Armour Thyroid,” my patient began to explain with a tone of appeal for me to take her seriously.
I trust my patients and I believe them, but her story was a bit strange — or at least, I have never heard of such an excuse prior. I’ve heard stories that people misplaced their medications or accidentally threw them away — but, a “dog eating the medication” was new to me.
“Tell me more about it,” I said.
She explained that she had forgotten the Armour Thyroid bottle on the kitchen counter in the morning, and when she returned from work she found her dog in a state of hyperactivity. As soon as she entered the kitchen, she realized what had happened. The dog must have grabbed the bottle, forced it open and ate all 87 Armour Thyroid 120 mg tablets out of the refill that was just renewed 3 days earlier.
She brought the bottle into the office with her to show me. The cap was damaged and partially chewed with marks of the dog’s canines clearly engraved on the cap. The top of the bottle was also partially damaged and distorted. There was clear evidence that the bottle was forced open, by a canine — the patient’s dog.
The next question I asked my patient was, “How did the dog do afterwards?”
She explained that she took him to the veterinary hospital and he survived. She stated that her veterinarian told her that dogs’ requirements of thyroid hormones are much higher than a human’s requirements.
Out of curiosity, and not sure if the patient would have a clue about the incident, I asked, “why do you think the dog attacked the medication bottle?”
She said that in the past she has forgotten to put other medications away but the dog would not mess with them. The patient has a background in health and added, “I guess the dog must have smelled the Armour Thyroid, a product of animal source.”
I was impressed by her elaboration. I knew very well that Armour Thyroid is of porcine origin, but it did not occur to me at that point in time.
I refilled her prescription and told her that I would research the topic.
I did an extensive literature search with the help of our senior medical librarians and found that there was very little literature about animal poisoning by human medications in the human medical literature. When I searched the veterinary literature I was shocked by the high prevalence of this phenomenon — I found that over 50% of annual calls to the Pet Poison Helpline, approximately 150,000 calls, were caused by human medications (Pet Poison HelpLine. Available at: http://www.petpoisonhelpline.com/pet-owners/basics/top-10-human-medications-poisonous-to-pets. Accessed on March 18, 2018; Merrill E. Top 10 human medications that are poisonous to dogs. The Dog Daily. Available at: http://www.thedogdaily.com/ca/health/safety/dog_poison/index.html. Accessed on March 18, 2018).
Of note, thyroid hormones were listed amongst the “Top 10” human medications to cause animal poisoning (Merrill E. Top 10 human medications that are poisonous to dogs. The Dog Daily. Available at: http://www.thedogdaily.com/ca/health/safety/dog_poison/index.html. Accessed on March 18, 2018; Hansen SR, et al. J Am Vet Med Assoc. 1992;200:1512-1514).
When I looked up Armour Thyroid prescription medical information by the manufacturer, it was explicitly stated that the medication is of porcine origin and it has a strong and characteristic smell. To evaluate this point personally I checked with one of our pharmacists who took a bottle of Armour Thyroid off the shelf and opened the bottle for me to smell. I also asked another patient who happened to bring a half-filled Armour Thyroid bottle with her to a clinic visit — the tablets had a strong animal smell that was stronger in the older bottle. The Armour Thyroid tablets smelled like dog food treats!
The strong odor of Armour Thyroid is conceivably a powerful factor in attracting dogs to this medication. However, from talking with a few veterinary doctors, as well as people who have pets, it appears that dogs are curious to play with any object found available around them. It may explain the high prevalence of pet poisoning due to various human medications. Therefore, it makes sense to keep all medications out of the reach of pets.
In relation to the risk of pet poisoning by human medications, there seems to be another problem besides the call for proper storage of medications. Some people try to give their own human medications to their pets!
Justine Lee, DVM, DACVECC, DABT, associate director of veterinary services at the Pet Poison Helpline, warns against that in a brief video presentation on the Pet Poison Helpline website. She states that some human medications are toxic to pets due to major differences in physiology and pharmacology even in the smallest routine human dose. For example, one tablet of acetaminophen can kill a dog. Lee emphasizes the need to separate human medication bottles from those of pets when stored in cabinets. A mix up of medications can be another cause of pet poisoning by human medications.
Having learned a great deal of knowledge from this case, I promised the patient that I would start a campaign to increase awareness amongst the public about the importance of keeping their medications away, not only from children but also from pets. I started the campaign by writing up the patient’s case as an abstract that will be presented at a national endocrine meeting later this spring in the hope of spreading the word about this overlooked issue. The case was also accepted by Endocrine Practice and was recently published (Aldasouqi SA, et al. Endocr Pract. 2018;doi:10.4158/1934-2403-24.3.315).
I hope this brief case presentation in the two aforementioned forms will raise awareness about the issue. While the audience in these two venues is limited to endocrinology clinicians, I hope this message gets spread beyond that audience. In addition, I have also discussed this intriguing issue with veterinary colleagues in the hope of collaborating joint research to study this phenomenon with the goal of proposing guidelines in the medical community to add a warning on all human medications to keep them away from pets.