Antidotes are sexy. We see it in James Bond and Indiana Jones movies: the hero has been slipped a lethal poison (usually, while wearing a tuxedo) and just in the nick of time swallows a vial of mysterious liquid that allows him to continue to save the day.
The word antidote can be described as the opposite or antonym of ‘poison.’ It comes from the Greek word antidoton, meaning ‘to give against’. A common misconception about antidotes is that every poison has one. It is a powerful idea: someone is severely poisoned, and all it takes is one dose, one drug that is the perfect opposite of the poison to cure them. However, this is only possible for very few poisons; the vast majority do not have
an antidote. Even though there are countless thousands of different toxins in existence, the number of known antidotes is under 50.
The history of poisoning dates back thousands of years—poisons have been used in hunting, war, homicide, executions and even medicine—and thus the search for antidotes has never been far behind. Back in the old days, (200 BC all the way up to the beginning of the 19th century), everyone was after a universal antidote. One concoction that would work against “all poisons and bites of venomous animals” and could be used both prophylactically (to prevent) and therapeutically (to treat). Seems pretty efficient right? Some famous antidoteurs include King Mithradates VI of Pontus (132-63 BC) and Andromachus (37-68 AD). Their universal antidotes (otherwise known as mithridatum, or theriac) contained up to 100 ingredients and involved elaborate preparation and aging processes. Unfortunately….they didn’t work. Any observable benefit was likely due to the massive opium content of these potions! For all the chemically diverse substances this world has to offer, there will never be one antidote or potion that will treat everything.
One thing to remember about antidotes is that they can be poisons in their own right. Remember that everything can be a poison; poison is a matter of dose. Too much of an antidote, the wrong antidote, or an antidote that is innately toxic can easily cause more harm than good in an already sick patient.
Here are the properties of an “ideal” antidote:
- It has a low order of toxicity itself Meaning it would take a huge overdose of the antidote to cause any symptoms, or the symptoms it does cause are minimal (or both). This is key when the exact toxin ingested is not known for sure. This happens more often than you might think. One examples: a patient comes in to the hospital unconscious, so can’t tell what they have been exposed to.
- It is easily prepared and administered The faster you can get the right dose into the patient, the better. An example of an effective antidote that does NOT fit this criteria is snakebite antivenin. It requires painstaking mixing of multiple vials and has to be given via IV in a very particular process. It works and has saved many lives but it really has to be done just right.
- Works quickly To go from near death, to ready to play poker again with one swallow (or injection into the neck) makes a great movie but that isn’t reality. For some poisons, it is too late for the antidote to be fully effective once symptoms have started to occur, so the sooner an antidote starts working, the better.
- It is effective. Seems like a no brainer, but medical history is filled with antidotes that hardly worked (or worse) that were given for years just because doctors and nurses felt like they had to do SOMETHING for a poisoned patient.
So what do we do for patients who have been poisoned or taken an overdose of something that does not have an antidote? Mainly, providing basic supportive care: there are many therapies that can treat specific symptoms of poisoning that aren’t necessarily considered antidotes. And luckily, some of the more common serious poisons DO have antidotes. Regardless of how a poison is treated, it is important to remember that the sooner treatment is started, the better the possible outcome. So if you ever expect that a poisoning has occurred (even if you are not sure!), call the poison center at 1-800-222-1222 to get expert advice on what treatment, if any, is needed. If you are a health care professional, and want more detailed information on antidotes, check out the Illinois Poison Center’s antidote stocking chart here.