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DMSA and blood-brain-barrier crossing

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DMSA is water soluble. It does not cross the BBB. —The preceding unsigned comment was added by 149.164.12.85 (talkcontribs) .

Sorry, you'll have to provide a source for that. Wikipedia prefers verifiability over truth. —Keenan Pepper 18:11, 19 June 2006 (UTC)[reply]
I added two references of peer-reviewed journals stating that DMSA does not cross the BBB.--83.41.120.246 (talk) 07:59, 4 March 2008 (UTC)[reply]
Calcium is water soluble. It does not cross the BBB. Except it does. Breedentials (talk) 22:43, 4 August 2015 (UTC)[reply]
Hello, I've checked the sources provided in order to support the claim that DMSA does not cross the brain barrier, and they actually are insufficient:
Source 1: Rooney, James (2007). "The role of thiols, dithiols, nutritional factors and interacting ligands in the toxicology of mercury". Toxicology. 234 (3): 145–156. doi:10.1016/j.tox.2007.02.016. PMID 17408840.
In this source, we can find about the DMSA BB crossing, the following:
"DMSA does not effectively chelate mercury in the brain (Aposhianet al., 2003; Buchet and Lauwerys, 1989; George et al.,2004)." (p. 150)
If you examine the phrase, it doesn't say "DMSA does not chelate mercury in the brain". It talks about "effectiveness". And, if we examine the George et al., study provided, "Mercury binding to the chelation therapy agents DMSA and DMPS and the rational design of custom chelators for mercury. Chem. Res. Toxicol. 17, 999–1006.", which is the only one concerning human brains among these three, we can find on its fourth page:
"Moreover, mercury in certain tissues (e.g. the brain) is known to be essentially impossible to remove using DMSA and DMPS [15]."
The "essentially" is important for a correct reading of the source. Here, the [15] refers to the study:
Clarkson, T. W., Magos, L., and Myers, G. J. (2003) The Toxicology of Mercury – Current Exposures and Clinical Manifestations. N. Engl. J. Med.349, 1731-1737.
If, finally, you check this source, which is the original source, you'll find a table, on page 1732 (the second page of the article), a table which summarizes the efficiency of DMSA on chelating the central nervous system.
This table provides 4 types of Mercury, and different way of exposure and target organs:
A) Mercury Vapor - target organs: Central nervous system, peripheral nervous system, kidney.
B) Inorganic Divalent Mercury - target organs: Kidney
C) Methyl Mercury - target organs: Central nervous system
D) Ethyl Mercury - target organs: Central nervous system, kidney.
In the cases A and B, the DMSA (Meso-2,3-dimercaptosuccinic acid) is used as a chelator agent. Only in the cases C and D, the :chelators are said as ineffective.
The author concludes: "Chelators can remove methyl and ethyl mercury from the body; they cannot reverse the damage to the :central nervous system. They may, how-ever, prevent further deterioration".
As a conclusion, it is not said that the DMSA cannot cross the BB.
It is a bad interpretation of the citations of both James Rooney and George et al.
Source 2: Guzzi, GianPaolo; Caterina A.M. La Porta (2008). "Molecular mechanisms triggered by mercury". Toxicology. 244 (1): 1–12. doi:10.1016/j.tox.2007.11.002. PMID 18077077.
In this article, page 5, the authors say: "DMSA does not cross the blood–brain barrier in animals and humans studies (Aaseth et al., 1995)".
But, in that study, Aaseth et al., 1995, state about the DMSA BB crossing, the following:
1) "DMSA was the most efficient agent in lowering the metal concentration in the target organ, and decreased the brain mercury :to about 35% of controls under our experimental condition" (page 853)
2) "It is still unknown if treatment with DMPS or DMSA can lower brain mercury levels, as these agents have not been fully :evaluated in mercury vapour poisoning." (page 854)
3) " In animal studies, repetitive injections of CaNa2EDTA did not reduce the concentration of lead in the brain, whereas comparable doses of DMSA were efficient ." (page 854)
Therefore, we can conclude that the statement in the Rooney study (2007) referring to the Aaseth study is erroneous.
The source 2 is, as a consequence, insufficient to support that claim.
To finish with this, we see here that both source 1 and source 2 does not provide enough material to claim that DMSA cannot cross the brain barrier. Eldieke (talk) 20:32

Quick Comment

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I have looked around the internet to find the following:

It states that the following holds : "A Closer Look at the Chelators

The most common chelators prescribed by the medical profession are EDTA, DMPS, and DMSA. These chelators are life-saving drugs in cases of acute metal poisoning. Of these, the DMSA and DMPS especially carry risks of harm, and should only be used as a last resort. "

Is this true? Does it not deserve mention on the wiki site in case someone tries something not necesarily so intelligent (such as to buy from the linked chemical suppliers page for their own personal mercury removal?). —temp_userbla 23:49, 29 November 2006 (UTC)[reply]

In the cited reference it is shown that DMSA crosses the BBB of mice, not of humans. Therefore the conclusion is, at least, disputed. I have changed the page accordingly. --Juliusllb 23:51, 11 February 2008 (UTC) —Preceding unsigned comment added by Juliusllb (talkcontribs)

NOTE: the CAS number listed is specific for the meso stereoisomer, whereas the name in the drugbox is unspecified as to stereoisomer —Preceding unsigned comment added by Reengler (talkcontribs) 17:21, 1 May 2008 (UTC)[reply]

MiaDMSA (CAS number: 142609-62-9) should be mentioned as well. There are many studies that show better efficiency at detoxing heavy metals. — Preceding unsigned comment added by 185.110.88.177 (talk) 20:24, 12 February 2022 (UTC)[reply]

Structure of complex

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DMSA chelating an atom of mercury

The structure looks funny. Ionizable groups are still protonated, and I wonder if complex is a monomer. Is this structure really from a crystal structure? --Smokefoot (talk) 13:26, 16 August 2009 (UTC)[reply]

No I just made it up.
I'll have a look for something a little more evidence-based.
Ben (talk) 17:06, 16 August 2009 (UTC)[reply]

3D-structure is wrong

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The 3D-structure shows the (2S,3S)-isomer not the meso-isomer as mentioned with the IUPAC name. Thus, the 3D-structure is wrong. Furthermore, the 2D-stucture is unclear, it may represent the meso-isomer as well as both enantiomers [(2S,3S)-isomer and (2R,3R)-isomer. Best regards, -- (talk) 12:07, 29 January 2011 (UTC)[reply]

If you look at the image description page for File:DMSA-3D-balls.png, you'll see that's it's based on Acta Cryst. C (1992) 48, 2007–2009, an experimental determination of the structure by x-ray crystallography. It is impossible that it is wrong. I have replaced the skeletal formula with a new one, File:Meso-2,3-dimercaptosuccinic-acid-2D-skeletal-A-configurations-labelled.png, showing the meso stereoisomer, which is the isomer actually used in medicine.
Ben (talk) 14:42, 29 January 2011 (UTC)[reply]

lead

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i added a sentence to the lead explaining that the acid is often used to treat heavy metal toxicity. in my opinion, that is one of the more important aspects of the article, so i thought a comment on it belonged in the lead. let me know if you'd like to work on that section with me. thank you. GoGatorMeds (talk) 19:39, 27 June 2014 (UTC)[reply]

Requested move 20 June 2022

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The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.

The result of the move request was: moved. Feel free to turn the ensuing redirect into a disambiguation page if appropriate. (closed by non-admin page mover) Extraordinary Writ (talk) 02:46, 27 June 2022 (UTC)[reply]


Dimercaptosuccinic acidSuccimer – Use the INN for the page name per WP:MEDMOS, WP:PHARMMOS Whywhenwhohow (talk) 01:37, 20 June 2022 (UTC)[reply]

The R,S isomer is the meso, which is succimer and is the focus of the current article given the chembox. We don't have articles on R,R or S,S. If the move is made, then the resulting redirect at Dimercaptosuccinic acid could be made into a chemindex once we have an article for either of the other isomers. Mdewman6 (talk) 20:12, 23 June 2022 (UTC)[reply]
The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.