Potential New Treatment for Some Types of Poisonings
I recently ran across a paper that talked about the potential benefits of an emerging therapy in the treatment of some types of pet poisonings. The therapy is called intravenous lipid emulsion, or ILE. It hasn’t been used much in veterinary medicine (research into its effects in human patients is more readily available), but it may represent a big advance in our ability to treat lipophilic (i.e., fat-loving) poisons.
My understanding is that ILE preparations consist of microscopic drops of oil, typically soybean oil, that are infused into a patient’s bloodstream. This is pharmaceutical grade oil, not what you have in your pantry. Similar ingredients have been included in total parenteral nutrition formulations (i.e., intravenous feeding) for years and appear to be quite safe.
We don’t know exactly how ILEs work, but it appears that they may act as a "sink" for fat soluble substances. In other words, rather than diffusing into the fatty tissues of the body where a poison can wreak havoc, it is held in the bloodstream where it can do less harm and eventually be eliminated.
One of the coolest things about ILEs is how fast they can work. In a case report that appeared in the Journal of the American Veterinary Medical Association (JAVMA), a border collie that ate a potentially fatal amount of horse dewormer containing ivermectin was sent home after only two days in the hospital, two treatments with an intravenous lipid emulsion, and standard supportive care. The owner reported that the dog was completely normal 48 hours after returning home, despite suffering from muscle tremors, hyperthermia (elevated body temperature), ataxia (unsteady and irregular walking movements that are caused by neurologic abnormalities), and blindness.
In another JAVMA case report, a cat developed severe lethargy, difficulty breathing, cardiovascular dysfunction, and low blood pressure after being overdosed with lidocaine. Fifteen minutes after being given intravenous lipid emulsion, the cat was more alert and able to hold his head up without assistance. By the time the infusion was finished, the cat seemed more aware of his surroundings and started to groom himself. The following morning, the cat appeared completely normal and his physical exam was unremarkable.
Poisonings that could potentially respond to ILE therapy include ivermectin, moxidectin, lidocaine, bupivaciane, propranolol, verapamil, clomipramine, permethrins, and baclofen. Even though these types of problems aren’t seen on a daily basis in a general veterinary practice, the low cost and long shelf life of ILEs make them something that could be easily kept on hand "just in case." My veterinary supplier sells a 250 ml bottle of a 20% ILE for just $11.65.
Dr. Jennifer Coates