Talk:Brodifacoum

Pharmacology

I suggest to change the section "Pharmacology" to "Toxicology". Reason: brodifacoum is used only in biocidal (rodenticidal) context, it has no pharmacologic relevance other than its toxicity. Since the only use of it is that of a poison per se, it is appropriate to discuss its dynamics and kinetics in organism as toxodynamics and toxokinetics, forming toxicology of the substance.

I therefore change the name of the section to "Toxicology".

I also add some toxicological values (half-life, LD₅₀ values, LC₅₀ value, estimated fatal dose for a human) from the sources quoted ( http://www.inchem.org/ ). --84.163.124.102 00:09, 8 October 2006 (UTC)

Excellent! Great stuff. I do wonder about this statement though (which I edited for clarity): "Dehydrated bodies also dry out more readily, possibly leaving an odorless, mummified carcass." Does anyone know about this? Is the dehydration caused by brodifacoum really significant enough to affect the manner of decomposition? It would be great to have a reference to back this up. Cheers -- FirstPrinciples 08:54, 18 October 2006 (UTC)

Okay, I mailed a producer of a 2nd gen. anticoagulant rodenticide bait (specifically, difethialone baits, not brodifacoum, but difethialone and brodifacoum are very closely akin), that claims the drying-mummification in their product prospects and they mailed me back:

"Rückfragen beim Hersteller haben ergeben, dass die Erkenntnis des schnellen Eintrocknens der Tiere auf Anwendungsbeobachtungen beruht und abhängig von den äußeren Bedingungen zu sehen ist."
which means
"A query by manufacturer brought, that the knowledge of fast drying of the animals [animal corpses] is based on application observations, and is seen dependant on external conditions".
So there are no real scientific observations/studies of this phenomenon yet, or I found none of the kind. I have thus no objections against removing the claim from the article, if it interferes somehow with the NPOW or objectivity of the article.--Spiperon 18:35, 25 October 2006 (UTC)

Well, in fact, most 2nd generation anticoagulants (most pronounced is this mummification by bromadiolone, brodifacoum and difethialone) cause dehydration (which is caused by the hypovolemia and capillary damage, leading to blood/plasma leakage and subsequent intesticial fluid compensation of progressive hypovolemia, and if the rodent doesn't drink water copiously, the dehydration thus obtained is quite significant and progressive; with damaged, leaking capillaries, the whole body becomes "leaking" and fast-drying in dry air) as far as I know, that results to prone drying of the carcass, as long as the surroundings are dry, not moist.

I observed this also in practice, when I used difethialone and brodifacoum baits against rats and mice, I found after some weeks, by cleanup of the area where rodents were active prior to baiting, multiple dry carcasses, with no signs of decay. The bodies were just like dryied in an exsiccator, perfectly conserved. When I first observed this, I was surprised, because the use of zinc phosphide or warfarin resulted often to decaying, badly smelling bodies all over the place. I think, that an association of an anticoagulant with an antibiotic (sulfaquinoxaline) results also to more likely dry-mummification, because of the reduction of the biggest internal reservoir of the bacteria -- the intestinal microflora. But I don't have any relevant scientific sources to support this thesis yet. Only claims supporting this I found so far are in descriptions of the rodenticidal products containing 2nd gen. anticoagulants by their manufacturers, in german. In general, claims of manufacturers are not reliable source of objective information in regard to its necessary bias, but my observations support them, so I simply accept it.--Spiperon 13:56, 18 October 2006 (UTC)

Humaneness

I think it should be mentioned in the article somewhere that Brodifacoum is not regarded as a humane way to kill animals. I didn't put this in myself as I wasn't sure if it had a good enough reference (nor was I sure how to reference it.) I found this paper - The Humaneness of Rodent Pest Control - G Mason, K E Littin - at the following address, which seems to describe anticoagulants as inhumane for rodent pest control. http://www.helpinganimals.com/pdfs/TheHumanenessOfRodentControlAnimal%20Welfare-2003.pdf Jatoo (talk) 11:26, 28 December 2007 (UTC)

Anticoagulants are quite consensually considered to be a "humane" method of exterminating vermin. What is a "humane way to kill", anyway?--(84.163.124.2 (talk) 15:51, 15 January 2008 (UTC)— Reassesed today--84.163.125.4 (talk) 16:59, 16 January 2008 (UTC))

Pit Bull Story

WTF? This has almost nothing to do with the main article. I don't think it belongs here. ---Zizanie13 (talk) 01:46, 9 June 2008 (UTC)

It has now been removed. -- Ed (Edgar181) 14:15, 20 October 2008 (UTC)

LD50 for cats: 0.25 or 25 mg/kg?

I have found contradictory LD50s for cats.

The article states 0.25mg/kg bodyweight, which agrees with the stated source http://www.inchem.org/documents/pds/pds/pest57_e.htm

but these sources state 25mg/kg:

http://www.inchem.org/documents/pims/chemical/pim077.htm#SubSectionTitle:7.2.2%20%20Relevant%20animal%20data

http://msds.orica.com/pdf/shess-en-cds-010-000000020872.pdf

25mg/kg seems surprisingly high and weirdly coincidental to be exactly 100x the minimum dog level so it may be a typo (rather shabby in an MSDS!)

Does anyone know for sure which is correct? —Preceding unsigned comment added by 203.129.55.68 (talk) 23:04, 23 December 2009 (UTC)

More sources: http://www.liphatech.com/vetguide.html http://www.the-piedpiper.co.uk/th15(k).htm http://pmep.cce.cornell.edu/profiles/rodent/rodent_A_L/brodifacoum/brodif_prf_0185.html

These all seem to indicate as well that the LD50 for a cat is extremely high. Indicating that baits of 0.005% would require consumption of a kilogram of bait to reach the LD50, or that the direct LD50 is in the range of 25mg/kg. I'm going to make the change, and use the data from the cornell.edu as source material, backed up by the inchem source indicating 25mg/kg, and finally the sources referenced by the liphatech.com source material. --Puellanivis (talk) 22:22, 6 July, 2010 (UTC)

Agreed. I've seen half a dozen sources noting that LD50 for cats is VERY high for this, although reports of cat deaths from eating it are still known. But 25 mg/kg as a single dose appears to be correct. SBHarris 02:38, 17 December 2010 (UTC)

Toxicity in cats

This source says c. 25 mg/kg (cat); here LD50 oral (cat) estimated as 25 mg/kg; but in here it is 0.25 mg/kg. This pdf says "Published LD50 values of brodifacoum for cats vary widely, from 25 mg kg-1 (Rammell et al., 1984;Godfrey, 1985) to 0.25 mg kg-1(Haydock and Eason, 1997).". Now what information should be used?--RicHard-59 (talk) 11:12, 12 February 2014 (UTC)

Here] is also 25 mg/kg.--RicHard-59 (talk) 11:19, 12 February 2014 (UTC)

Changed to: cats (oral) 0,25 mg/kg — 25 mg/kg with appr. refs.--RicHard-59 (talk) 12:14, 12 February 2014 (UTC)

Vitamin C

I removed the line about vitamin C being used as an antidote. While there is a reference given for it in the safety sheet, I'm not aware of vitamin C being used clinically. Please correct me if is indeed used. Andrew73 (talk) 18:22, 12 November 2012 (UTC)

Wait. 1. The reference is not a "safety sheet" but the FAO/WHO poison data sheet, that being quite a difference; 2. the source quoted nor the text in the article did postulate an antidotal use of vitamin C, it is mentioned only as an adjunct to the causal therapy, i.e. vitamin K₁ ± coagulation factors concentrate IV; 3. you are not aware of vitamin C being used clinically? How often do you treat brodifacoum toxicoses (not meaning overdoses of Coumadin and the like)? Cheers,--134.3.94.175 (talk) 15:09, 18 October 2013 (UTC)

What is its efficacy vis-à-vis other poisons? Causes death how? What time-frame? How humanely? Why not use a human euthanasia agent?

Article seems to infer material takes some little time to kill. Days? Weeks? Manifestly, the longer it takes to kill, the very much less efficacious a poison it is. Not much use if a pregnant rat could still deliver another litter, say.

Causes unconsciousness. So death is effected how, typically? Starvation? Predation? Low blood pressure?

Anyone have any idea why pests can't be poisoned rather more humanely, and quickly, the way humans overwhelmingly choose to euthanase themselves? That is, with benzodiazepines? — Preceding unsigned comment added by 49.180.120.236 (talk) 03:00, 20 January 2014 (UTC)

Rats are Ungeziefer — Preceding unsigned comment added by 91.21.102.33 (talk) 09:41, 4 April 2014 (UTC)

Okay. I try to explain some of your questions.

1. "Article seems to infer material takes some little time to kill. Days? Weeks?"

Generaly speaking, brodifacoum like all coumarin anticoagulants do cause progressive toxicosis leading to death in a timespan of between 2 and 10 days after the ingestion of a lethal dose. This is similar for every indirect anticoagulant and has to do with the mechanism of action being progressive, rather slow, as described.

2. "Manifestly, the longer it takes to kill, the very much less efficacious a poison it is."

No, in rats, the opposite is true: quickly acting poisons are ineffective because rats are socially intelligent and learn rather quickly, that a bait which causes fast poisoning is to be ommited. This has to do with the inherent biology and behavioral traits of rats.

3. "Not much use if a pregnant rat could still deliver another litter, say."

Another reason why anticoagulants are so effective as rat poisons is that they cause abortions in pregnant female rats, even in sublethal doses. That is, if a pregnant female rat consume even a minimal amouth of an anticoagulant, she will certainly not deliver any living offspring.

4. "Causes unconsciousness. So death is effected how, typically? Starvation? Predation? Low blood pressure?"

Typically, the immediate cause of death is the blood loss. You see, rats very much like humans, can bleed to death; actually, given their relatively low intravascular blood volume, they bleed to death rather easily if poisoned by an anticoagulant such as brodifacoum.

5. "Anyone have any idea why pests can't be poisoned rather more humanely, and quickly, the way humans overwhelmingly choose to euthanase themselves? That is, with benzodiazepines?"

See 1.. Rat poison in order to be effective has to act slowly and with a distinctive latency period, so that the other rats from the pack don't realize they are feeding on a poison and/or don't associate the bait with dying. As for the "humaneness", let's be honest: what is a humane way of poisoning a mammal, after all. One that sounds more nicely? Like to die of suffocation in coma sounds more nicely than to die in coma from blood loss? Frankly, I don't see the point in this.

Anticoagulants such as brodifacoum certainly can cause pain and suffering before death occurs, like if a blood vessel ruptures and leads to haemorrhage into a joint or in the cerebral cavity; however most of the poisoned rodents die rather calmly, after falling asleep from the blood loss. The bleeding itself is not caused by a trauma, but by a biochemical/enzymatic mechanism and as such is not painful per se. Many folks associate blood loss with grave injuries and therefore pain, but the process of loosing blood by itself is not particulary painful and leads to loss of consciousness, coma and death without an agony (c.f. exsanguination by opening the arteries in a hot tub). Cheers,--134.3.105.168 (talk) 15:06, 3 May 2014 (UTC)

Brodifacoum

Several news organizations report that a lab report confirmed the existence of the rat poison in the inmates' food. Unless counterevidence turns up, we should go with the weight of the sources. HGilbert (talk) 17:39, 30 April 2015 (UTC)

But do you understand the difference between a piece of meat (smuggled out by a prisoner) and a human being poisoned? That would be like yourself if you bought a burger from McDonalds, put poison in after leaving and coming back saying you'll sue, any court case would need proof YOU were poisoned and not just the piece of MEAT. That would be proven with blood or urine.

Do you get where i am coming from?

The way the page is currently it suggests that further tests have already been carried out. I mean one extra sentence could clear that up, i dont see why that is a major problem. Disappeared353 (talk) 08:30, 3 May 2015 (UTC)

I have clarified the text accordingly. HGilbert (talk) 09:45, 3 May 2015 (UTC)

various problems

IUPAC name - the IUPAC name is inconsistent with the structure shown; the IUPAC name is a different tautomer. This needs an explanation. Chemical synthesis - it would be better to say brodifacoum is a member rather than derivative of the 4-hydroxycoumarin (no -) group. Is the commercial product a pure stereoisomer? If so, the structure and name should indicate it. If not, why is a stereospecific synthesis given? It doesn't make sense to say compound 1 is the starting ester then describe how it is made from another ester. I suggest something like: Compound 1 can be made by a simple Wittig condensation of ethyl chloroacetate with 4'-bromobiphenylcarboxaldehyde. I recommend "reaction" instead of "then reacted". "addition of" should be deleted. Toxicology - Why is "T+" & "N" shown? Is this part of some designation system? If so, explain. "resorptivity" should presumably be "absorptivity". Brand names - d-CON (and maybe many of the others) no longer uses brodifacoum. See cen.acs.org/articles/92/i23/Maker-Rat-Poison-d-CON.html. Treatment for humans - Should "all 3-6 hours" be "every 3-6 hours"? Poisoning case reports - Should "Contrac" be "Contac"? References - 12 is missing a space. 13 appears to be missing a g. Categories - Brodifacoum is not a drug. (from 4-hydroxycoumarins entry: "The second-generation vitamin K antagonist agents, used only in this fashion as poisons (because their duration of action is too long to be used as pharmaceuticals) include..." 69.72.92.1 (talk) 05:05, 16 December 2015 (UTC)

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