An antidote is a substance that can counteract a form of
poison
Poison is a chemical substance that has a detrimental effect to life. 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 figuratively, with a broa ...
ing. The term ultimately derives from the Greek term φάρμακον ἀντίδοτον ''(pharmakon) antidoton'', "(medicine) given as a remedy". 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 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 ...
produced by certain species of
snake
Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes . Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more j ...
s,
spider
Spiders (order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species d ...
s, and other venomous animals. Some animal venoms, especially those produced by
arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...
s (such as certain
spider
Spiders (order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species d ...
s,
scorpion
Scorpions are predatory arachnids of the order Scorpiones. They have eight legs, and are easily recognized by a pair of grasping pincers and a narrow, segmented tail, often carried in a characteristic forward curve over the back and always endi ...
s, and
bee
Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyly, monophyletic lineage within the ...
s) are only potentially lethal when they provoke allergic reactions and induce
anaphylactic shock
Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the follow ...
; as such, there is no "antidote" for these venoms; however anaphylactic shock can be treated (e.g. with
epinephrine).
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
A tourniquet is a device that is used to apply pressure to a limb or extremity in order to stop the flow of blood. It may be used in emergencies, in surgery, or in post-operative rehabilitation.
A simple tourniquet can be made from a stick an ...
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 venom antidote using
CRISPR
CRISPR () (an acronym for clustered regularly interspaced short palindromic repeats) is a family of DNA sequences found in the genomes of prokaryotic organisms such as bacteria and archaea. These sequences are derived from DNA fragments of bac ...
. 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.
List of antidotes
See also
*
Antitoxin
*
Antivenom
*
Snakebite
A snakebite is an injury caused by the bite of a snake, especially a venomous snake. A common sign of a bite from a venomous snake is the presence of two puncture wounds from the animal's fangs. Sometimes venom injection from the bite may oc ...
*
Universal antidote
*
Shapur ibn Sahl
References
{{Authority control