Thread: Poisons & Antidotes

So I'm kicking around an idea for a work of fiction.

Does anyone know chemicals/poisons/etc. that would work like this:

Scenario 1
If the body ingests A, it is harmful.
If the body ingests B, it is harmful.
If the body ingests A & B, the substances are neutralized.

Scenario 2
If the body ingests A, it is harmful.
If the body already contains B, then A is ineffective.

If there are many examples, what is a good example related to something a murderer would try to use?

Well, toxicology isn't my area, but I would venture the following:

For scenario 2, substance A could be methanol and substance B could be ethanol (e.g. if you were the murderer you could drink ethanol (alcoholic beverages) first then share methanol laced drinks with your victim) (you would need to check this with someone who knows more than me)

I don't know about scenario 1. but if it was a scenario where component A and component B were not toxic on their own but toxic together then try Ricin.

You may be interested to read the book: Molecules of Murder by John Emsley

Warfarin and Vitamin K, possibly? (For 1, at least)

Originally Posted by Strange

Warfarin and Vitamin K, possibly? (For 1, at least)

is vit K toxic?

according to wiki (Vitamin K - Wikipedia, the free encyclopedia)

"no known toxicity is associated with high doses of the phylloquinone (vitamin K₁) or menaquinone (vitamin K₂) forms of vitamin K, so no tolerable upper intake level (UL) has been set"
(although they do mention a synthetic form that is toxic)

Originally Posted by SHF

is vit K toxic?

Apparently not.

Originally Posted by SHF

Originally Posted by Strange

Warfarin and Vitamin K, possibly? (For 1, at least)

they do mention a synthetic form that is toxic)

So what do you guys think - would Warfarin and "synthetic" Vitamin K cancel each others' toxicity out if ingested/injected?

Originally Posted by SHF

if you were the murderer you could drink ethanol (alcoholic beverages) first then share methanol laced drinks with your victim) (you would need to check this with someone who knows more than me)

I don't know about scenario 1. but if it was a scenario where component A and component B were not toxic on their own but toxic together then try Ricin.

You may be interested to read the book: Molecules of Murder by John Emsley

Thanks for the info - if anyone can confirm the ethanol methanol theory, I'd apprecitate.

If you are genuinely writing a book then I would email some professors of toxicology. Coming on forums like this is good, but ultimately all you will get is suggestions that may or may not be right and you will need to get authoritative conformation. Give Emsley or whoever an email, it won't take them a moment to give you an accurate answer, and if you are writing a book they may be interested to discuss the nuances of the toxin application and so forth in your story. Also I'm sure there are a ton of crime novels with such details in them, I presume you have read many of these if you are embarking on writing one, so perhaps scan back through your collection.

MarcoPolo Im sorry I cant help you on this. I dont mean to hijack your post but since you already made a thread on poisons Id like to ask a sidequestion here. (If you dont approve let me know and I will remove it)

I was wondering if the human body can become immune to poisons by exposing themselves to them on purpose. If you take snake venom as an example, from a Cobra. And take a non-lethal dose. Does your body build a resistance to it? Meaning you could gradually take cobra venom to the point a bite will not be lethal anymore. Also how is venom and poison seperated in this regard?

There was a documentary on discovery about a man who tried to kill his wife with arsenikk I believe. WHen she didnt die he gradually upped the dosage. Instead of dying the guy got caught but the wife - in the end - survived dosages of arsenikk that would have killed any other person.

There was a documentary on discovery about a man who tried to kill his wife with arsenikk I believe. WHen she didnt die he gradually upped the dosage.

The gradual dosage thing depends strictly on the poison in question. Arsenic, mercury, lead are variously capable of chronic or acute or cumulative poisoning. For tolerance effects, all you have to do is look at the impact of a certain amount of alcohol on someone who's never had it before compared to an alcoholic who soaks up that amount or more each and every day. A full bottle of spirits could kill (or seriously endanger) a naive metabolism where it would just keep the alcohol addict's metabolism ticking over.

When it comes to venom I think it, again, depends on the animal in question.

The common mantra in all things is "The dose makes the poison". But the 'dose' and its mechanism differs from poison to poison.

I know that cyanide is made ineffective as a poison by lots of sugar, as was demonstrated in the famous assassination attempt of Rasputin, who ingested ice cream laced with cyanide and lived. He later had to be stabbed and shot.

Originally Posted by pyoko

I know that cyanide is made ineffective as a poison by lots of sugar, as was demonstrated in the famous assassination attempt of Rasputin, who ingested ice cream laced with cyanide and lived. He later had to be stabbed and shot.

Thanks for the tip. I'm going to put this here for my reference from wiki:

One theory on the apparent immunity of Grigory Rasputin to cyanide was that his killers put the poison in sweet pastries and madeira wine, both of which are rich in sugar; thus, Rasputin would have been administered the poison together with massive quantities of antidote. One study found a reduction in cyanide toxicity in mice when the cyanide was first mixed with glucose.[19] However, as yet glucose on its own is not an officially acknowledged antidote to cyanide poisoning.

The common belief that there is an antidote for every poison is in error. This harks back to the prescientific medical theories like the doctrin of signatures. That was the idea that a benevolent diety marked various herbs and substances so that people could identify what they were good for. That is why we have a medicinal herb called "hepatica" that is supposed to be good for the liver because it has 3 lobed brownish leaves that look like liver. There are substances that will counteract some poisons but the general rule is if you take poisonous substance a and poisonous substance b then you ae poisoned with substances a and b.

Originally Posted by Raziell

I was wondering if the human body can become immune to poisons by exposing themselves to them on purpose. If you take snake venom as an example, from a Cobra. And take a non-lethal dose. Does your body build a resistance to it? Meaning you could gradually take cobra venom to the point a bite will not be lethal anymore. Also how is venom and poison seperated in this regard?

It is possible with certain poisons however heavy metals, such as arsenic, do not work the same way. For arsenic and other metals to kill it takes a build up over time. The same thing can happen with silver or other metals as well. Once the body has enough it will shut down. Many naturally occuring toxins found in plant, insect, and animal venoms can be taken in small doses and an immunity can develop. I know a man in Western North Dakota who handles rattlesnakes regularly. He has been bitten so many times that he only gets mild bruising around the site and an upset stomach now.

Hmm.... Although not exactly poisons, A = Acid, and B = Base.

Originally Posted by jrmonroe

Hmm.... Although not exactly poisons, A = Acid, and B = Base.

Although there are exceptions, A+B is more likely to = (A+B) than it is to =0. Taking two poisons will make you poisoned with two things not unpoisoned. It would depend on the biologic actions of the chemicals involved. Crude factors like acid /base would simply be overwhelmed by the powerful acid enviornment of the stomach.

Originally Posted by Raziell

I was wondering if the human body can become immune to poisons by exposing themselves to them on purpose. If you take snake venom as an example, from a Cobra. And take a non-lethal dose. Does your body build a resistance to it?

Hey, it’s quite interesting when you look into the molecular level of it.

‘Immune' or 'immunity' wouldn't be the words (in the sense of developing memory B cells to deal with future encounters), but rather ‘adaptation’ or ‘tolerance’ (as mentioned by adelady, who also gave the example of alcohol tolerance; indeed we can ‘build up’ a tolerance to many substances - opioid tolerance is commonly encountered in medical practice).

This adaptation is multilevel (molecular / cellular / organ / systems level).

There are a few mechanisms through which the adaptation / tolerance develops:

(i) Reducing delivery of toxin to its target (e.g. by reducing absorption, increasing sequestration, enhancing detoxication, increasing cellular export)

(ii) Decrease size or susceptibility of target (e.g. receptor desensitisation, reduced receptor number (receptor down regulation)) (this is the mechanism for opioid tolerance – down regulation of mu receptors and up regulation of adenyl-cyclase signalling)

(iii) Increased capacity of organism to repair itself (e.g. induction of enzymes that repair oxidised proteins, induction of chaperones (see heat-shock proteins and endoplasmic-reticulum stress response), induction of enzymes repairing DNA)

(iv) Strengthened mechanisms to compensate the toxicant-inflicted dysfunction – adaptation by compensating the dysfunction that is; dysfunctions caused by toxicants or drug overdose manifested at the level of organism (e.g. hypoxia), organ system (e.g. hypo or hypertension), or organ (e.g. renal tubular dysfunction) may evoke compensatory mechanisms. This might include the hypoxic response (see HIF transcription factor which transactivates genes with HRE in their promoter, such as EPO, VEGF, proteins facilitating anaerobic resp, etc), also the energy stress response (see AMPK and its response to a drop in the ATP:AMP ratio), also neurohumoral mechanisms (e.g. hyperventilation during acute hypoxia, or RAAS in hypotension)


Mechanistically, adaptation involves sensing the noxious chemical and/or the initial damage or dysfunction, and a response that typically occurs through altered gene expression.

(You got me digging into my Casarett and Doull’s Toxicology)

Originally Posted by Sealeaf

The common belief that there is an antidote for every poison is in error.

Stated well.

I will take it a titch further. The reality is that there are almost no antidotes to poisons at all. They are a marked rarity. There are, of course, treatments for poisons. Eventually, the human body will break down, or get rid of most poisons, if it can survive long enough. If medical treatment permits a poisoned person to survive long enough, the poison will be gone, though permanent damage, including brain damage, may remain.