Antidote

An **antidote** is a chemical or medicine that will reverse the effects of some poisons. An antidote will make some or all of the effects of the poison go away.

Each antidote only works for certain poisons.

Not every poison has an antidote. For example, the poison aconitine has no known antidote. Aconitine is a very poisonous toxin that comes from the *Aconitum* plant. If enough of the poison enters a person's body, the person often dies.

## Examples of antidotes
### Activated charcoal
Activated charcoal can be used as an antidote for many poisons, but only poisons that were swallowed. For example, activated charcoal can be used for some drug overdoses, and for some poisonings. The charcoal attaches to the poison and keeps it from being taken into the bloodstream through the stomach.

Activated charcoal will not work for every kind of poison. For example, it will not work for alcohol, strong acids, and products made of petroleum (like paint thinner and fuel oil).

### Atropine
Sometimes, antidotes are poisons themselves. For example, atropine, which is found in deadly nightshade, is very poisonous. However, because of the way it reacts with the body, atropine is used as an antidote against some insecticides and certain kinds of nerve gas. Atropine is carried on many ambulances because it has other uses. For example, it can help restart a heart that is not beating. It is also used in Surgery.

One product - called DuoDote - that combines atropine with a medicine called pralidoxime chloride (also called 2-PAM). Both medicines are antidotes against some insecticides and nerve gases. DuoDote is given by injection intramuscularly or IM (through a needle into the thigh muscle). It comes in an auto-injector, which looks like a large pen. When its safety cap is taken off and the auto-injector is pushed against the thigh, it will automatically send the needle into the thigh and deliver the medicines. DuoDote is not carried on many ambulances, but some special teams that specialize in treating poisons carry them.

That medicine is called sodium thiosulfate. This medicine sticks to cyanide, and never un-sticks. 
It helps make cyanide into another chemical that is not poisonous. This new chemical can easily be removed from the body by the kidneys, through urination.

Ethanol also works as an antidote for methanol poisoning. Methanol is sometimes called "wood alcohol." It is also used in antifreeze, fuel, and solvents. People can get methanol poisoning accidentally by getting methanol on their skin or breathing it in. Methanol is also poisonous if it is drunk.

### Vitamin K 
Vitamin K is an antidote for warfarin (Coumadin) poisoning. Warfarin is a medicine which makes the blood thinner. It is used to prevent blood clots. However, if a person is given too much warfarin, their blood can get too thin. When the blood is too thin, it cannot clot. This can cause serious bleeding problems. 

The blood needs vitamin K to be able to clot. When a person has warfarin poisoning, giving them vitamin K can make their blood able to clot again.

It takes vitamin K four to six hours to reverse warfarin poisoning. Because of this, if a person with warfarin poisoning is bleeding, doctors may also give fresh frozen plasma. This will work more quickly to make the blood less thin.

## References