An antidote is a substance that can counteract a form of
poison
A poison is any chemical substance that is harmful or lethal to living organisms. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figurati ...
ing. The term ultimately derives from the Greek term φάρμακον ἀντίδοτον ''(pharmakon antidoton)'', "(medicine) given as a remedy". An older term in English which is now rare is atterlothe, derived from "
atter" ("poison" or "venom"). Antidotes for anticoagulants are sometimes referred to as reversal agents.
The antidotes for some particular
toxins are manufactured by injecting the toxin into an animal in small doses and extracting the resulting
antibodies
An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as bacteria and viruses, including those that caus ...
from the host animals' blood. This results in an
antivenom that can be used to counteract
venom
Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...
produced by certain species of
snake
Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...
s,
spider
Spiders (order (biology), order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude spider silk, silk. They are the largest order of arachnids and ran ...
s, and other venomous animals. Some animal venoms, especially those produced by
arthropod
Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...
s (such as certain
spider
Spiders (order (biology), order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude spider silk, silk. They are the largest order of arachnids and ran ...
s,
scorpion
Scorpions are predatory arachnids of the Order (biology), order Scorpiones. They have eight legs and are easily recognized by a pair of Chela (organ), grasping pincers and a narrow, segmented tail, often carried in a characteristic forward cur ...
s, and
bees) are only potentially lethal when they provoke allergic reactions and induce
anaphylactic shock; as such, there is no "antidote" for these venoms; however anaphylactic shock can be treated (e.g. with
epinephrine
Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands a ...
).
Some other toxins have no known antidote. For example, the poison
batrachotoxin – a highly poisonous
steroidal alkaloid derived from various
poison dart frogs, certain beetles, and birds – has no antidote, and as a result, is often fatal if it enters the human body in sufficient quantities.
Mechanical approaches
Ingested poisons are frequently treated by the oral administration of
activated charcoal, which
adsorbs the poison and flushes it from the digestive tract, thereby removing a large part of the toxin.
Poisons which are injected into the body (such as those from bites or stings from venomous animals) are usually treated by the use of a constriction band which limits the flow of lymph and/or blood to the area, thus slowing the circulation of the poison around the body. This should not be confused with the use of a
tourniquet which cuts off blood flow completely – often leading to the loss of the limb.
Techniques to identify antidotes
In early 2019, a group of researchers in Australia published the finding of a new
box jellyfish
Box jellyfish (class Cubozoa) are cnidarian invertebrates distinguished by their box-like (i.e., cube-shaped) body. Some species of box jellyfish produce potent venom delivered by contact with their tentacles. Stings from some species, including ' ...
venom antidote using
CRISPR
CRISPR (; acronym of clustered regularly interspaced short palindromic repeats) is a family of DNA sequences found in the genomes of prokaryotic organisms such as bacteria and archaea. Each sequence within an individual prokaryotic CRISPR is d ...
. The technology had been used to functionally inactivate genes in human cell lines and identify the peripheral membrane protein
ATP2B1, a calcium transporting ATPase, as one host factor required for box jellyfish venom
cytotoxicity
Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are toxic metals, toxic chemicals, microbe neurotoxins, radiation particles and even specific neurotransmitters when the system is out of balance. Also some types of d ...
.
List of antidotes
See also
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Antitoxin
An antitoxin is an antibody with the ability to neutralize a specific toxin. Antitoxins are produced by certain animals, plants, and bacterium, bacteria in response to toxin exposure. Although they are most effective in neutralizing toxins, the ...
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Antivenom
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Snakebite
*
Universal antidote
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Shapur ibn Sahl
References
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