View source for Antidote

{{Short description|Substance that can counteract a form of poisoning}}
{{Other uses}}
{{Distinguish|anecdote}}
An '''antidote''' is a substance that can counteract a form of [[poison]]ing.<ref>{{DorlandsDict|one/000006009|antidote}}.</ref> 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, venom, morbid fluid").<ref>{{cite web |title=atterlothe |url=https://www.oed.com/dictionary/atterlothe_n?tab=meaning_and_use |website=OED |access-date=27 December 2024}}</ref> Antidotes for anticoagulants are sometimes referred to as '''reversal agents'''.<ref>{{cite journal| pmc=4899056 | pmid=27330657 | doi=10.5811/westjem.2016.3.29294 | volume=17 | issue=3 | title=Anticoagulation Reversal and Treatment Strategies in Major Bleeding: Update 2016 | year=2016 | author=Christos S, Naples R | journal=West J Emerg Med | pages=264–70}}</ref>

The antidotes for some particular [[toxins]] are manufactured by injecting the toxin into an animal in small doses and extracting the resulting [[antibody|antibodies]] from the host animals' blood. This results in an [[antivenom]] that can be used to counteract [[venom (poison)|venom]] produced by certain species of [[snake]]s, [[spider]]s, and other venomous animals. Some animal venoms, especially those produced by [[arthropod]]s (such as certain [[spider]]s, [[scorpion]]s, and [[bee]]s) 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]]).

Some other toxins have no known antidote. For example, the poison [[batrachotoxin]] &ndash; a highly poisonous [[steroidal alkaloid]] derived from various [[poison dart frog]]s, certain beetles, and birds &ndash; 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 [[adsorption|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.<ref>{{Cite journal|last1=Smith|first1=T. A.|last2=Figge|first2=H. L.|date=October 1991|title=Treatment of snakebite poisoning|journal=American Journal of Hospital Pharmacy|volume=48|issue=10|pages=2190–2196|issn=0002-9289|pmid=1781479}}</ref>  This should not be confused with the use of a [[tourniquet]] which cuts off blood flow completely &ndash; 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]].<ref>{{Cite web|url=https://the-crispr.com/antidote-to-deadly-jellyfish-identified-using-crispr/|archive-url=https://web.archive.org/web/20190713055014/https://the-crispr.com/antidote-to-deadly-jellyfish-identified-using-crispr/|url-status=usurped|archive-date=July 13, 2019|title=Antidote to deadly jellyfish identified using CRISPR|last=The-Crispr|date=2019-05-13|website=The Crispr|language=en-US|access-date=2019-08-08}}</ref> 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]].<ref>{{Cite journal|last1=Neely|first1=G. Gregory|last2=Seymour|first2=Jamie E.|last3=Hesselson|first3=Daniel|last4=Nguyen|first4=David T.|last5=Qiao-Ping Wang|last6=Khuong|first6=Thang M.|last7=Oyston|first7=Lisa|last8=Littleboy|first8=Jamie B.|last9=Manion|first9=John|date=2019-04-30|title=Molecular dissection of box jellyfish venom cytotoxicity highlights an effective venom antidote|journal=Nature Communications|language=en|volume=10|issue=1|pages=1655|doi=10.1038/s41467-019-09681-1|pmid=31040274|pmc=6491561|bibcode=2019NatCo..10.1655L|issn=2041-1723}}</ref>

==List of antidotes==
{| class="sortable wikitable"
|-
!width=350pt| Agent
! Indication
|- 
 |  [[Activated charcoal]] with [[sorbitol]] 
 |  Used for many oral toxins
|- 
 |  [[Theophylline]] or [[Caffeine]]
 |  [[Adenosine]] receptor [[agonist]] poisoning
|-
 |  [[Antimuscarinic]] drugs (e.g. [[Atropine]])
 |  [[Organophosphate]] and [[carbamate]] insecticides, [[nerve agent]]s, some [[Mushroom poisoning|poison mushrooms]] 
|- 
 |  [[Beta blocker]] 
 |  [[Theophylline]]
|- 
 |  [[Calcium chloride]]<ref name="Calcium channel blocker poisoning">{{cite web | title=Calcium channel blocker poisoning | website=UpToDate | url=https://www.uptodate.com/contents/calcium-channel-blocker-poisoning | access-date=2019-07-09}}</ref>
 | [[Calcium channel blocker toxicity]],<ref name="Calcium channel blocker poisoning"/> [[Latrodectus|black widow spider]] bites
|- 
 |  [[Calcium gluconate]]<ref name="Calcium channel blocker poisoning"/>
 |  [[Calcium channel blocker toxicity]],<ref name="Calcium channel blocker poisoning"/> [[hydrofluoric acid]] burns
|- 
 |  [[Chelator]]s such as [[EDTA]], [[dimercaprol]] (BAL), [[penicillamine]], and 2,3-[[dimercaptosuccinic acid]] (DMSA, succimer) 
 |  [[Toxic heavy metal|Heavy metal poisoning]]
|- 
 |  [[Cyanide]] antidotes ([[hydroxocobalamin]], [[amyl nitrite]], [[sodium nitrite]], or [[thiosulfate]]) 
 | [[Cyanide poisoning]]
|- 
 |  [[Cyproheptadine]] 
 | [[Serotonin syndrome]]
|- 
 |  [[Deferoxamine]] mesylate 
 |  [[Iron poisoning]] 
|- 
 |  [[Digoxin Immune Fab]] antibody (Digibind and Digifab) 
 |  [[Digoxin toxicity|Digoxin poisoning]], [[Oleander]] ingestion <ref>{{Cite web|url=https://calpoison.org/news/cardiac-glycoside-poisoning|title=Naturally Occurring Cardiac Glycoside Poisoning · California Poison Control System (CPCS)}}</ref>
|- 
 |  [[Diphenhydramine hydrochloride]] and [[benztropine mesylate]] 
 |  [[Extrapyramidal symptoms|Extrapyramidal]] reactions associated with [[antipsychotic]]s
|- 
 |  100% [[Ethanol]] or [[fomepizole]] 
 |  [[Ethylene glycol poisoning]] and [[Methanol toxicity|methanol poisoning]] 
|- 
 |  [[Flumazenil]] 
 |  [[Benzodiazepine overdose]]
|- 
 |  100% [[oxygen]] or [[hyperbaric oxygen therapy]] (HBOT) 
 |  [[Carbon monoxide poisoning]] and [[cyanide poisoning]]
|-
 |  [[Idarucizumab]]
 |  Reversal of [[dabigatran etexilate]], an [[anticoagulant]]
|- 
 |  [[Insulin]] + [[Glucagon]] 
 |  [[Beta blocker]] poisoning and calcium channel blocker poisoning
|- 
 |  [[Leucovorin]] 
 |  [[Methotrexate]], [[trimethoprim]] and [[pyrimethamine]] overdose 
|-
 | [[Intralipid]]
 | [[Local anesthetic#Treatment of overdose: "Lipid rescue"|Local Anesthetic]] toxicity
|- 
 |  [[Methylene blue]] 
 |  Treatment of conditions that cause [[methemoglobinemia]] 
|- 
 |  [[Naloxone hydrochloride]] 
 |  [[Opioid overdose]]
|- 
 |  [[N-acetylcysteine]] 
 |  [[Paracetamol toxicity|Paracetamol]] (acetaminophen) poisoning
|- 
 |  [[Octreotide]] 
 |  Oral [[hypoglycemic]] agents 
|- 
 |  [[Pralidoxime chloride]] (2-PAM) 
 | When given with Atropine: [[Organophosphate]] insecticides, [[nerve agent]]s, some [[Mushroom poisoning|poison mushrooms]] 
|- 
 |  [[Protamine sulfate]] 
 |  [[Heparin]] poisoning 
|- 
 |  [[Prussian blue]] 
 |  [[Thallium poisoning]]
|- 
 |  [[Physostigmine]] sulfate 
 |  [[Anticholinergic]] poisoning
|- 
 |  [[Pyridoxine]] 
 |  [[Isoniazid]] poisoning, ethylene glycol, accidental hydrazine exposure (E.G from [[Gyromitra]] mushrooms)
|- 
 |  [[Phytomenadione]] (vitamin K) and [[fresh frozen plasma]] 
 |  [[Warfarin]] overdose and some (but not all) rodenticides 
|- 
 |  [[Sodium bicarbonate]] 
 |  [[Aspirin]], [[Tricyclic antidepressant|TCAs]] with a wide QRS{{clarify|date=August 2019}}
|- 
 | I.V [[Silibinin]]
 | [[Amatoxin]] ingestion 
|-
 |  [[Succimer]], chemical name Dimercaptosuccinic acid (DMSA)
 |  [[Lead poisoning]]
|}

==See also==
{{Wiktionary}}

* [[Antitoxin]]
* [[Antivenom]]
* [[Snakebite (bite)|Snakebite]]
* [[Universal antidote]]
* [[Shapur ibn Sahl]]

==References==
{{Reflist}}

{{Major drug groups}}
{{Antidotes}}
{{Toxicology}}

{{Authority control}}

[[Category:Antidotes| ]]