How much Gd is retained and how long will it take to get it all out?
This is my response to a question sent to me (see at bottom)
I have heard from another patient the description of the amount 1% of Gd being retained... which I believe some quasi-expert once blew out that number off the top of their head with no science behind it.
The story of retention actually is remarkably complex. In someone with normal renal function there is constant elimination of Gd from the body, so the amount retained naturally is always on the decline - so the time point in relation to injection is essential when considering the amount retained, to begin with. Gd also resides in a number of tissue/organ compartments with different retention constants, and that also equilibrate with one another.
Having said that, it is probably not the worst estimate. As I tell patients, I am not aiming to remove all the Gd, as it would be impossible, based on how it is retained in bone and the length of time to remove it from bone. I am aiming to get enough Gd out to get them to feel better. I supplement with other medications etc, a work in progress, to diminish the host reaction to what is left. I may have to post a blog on this.
I generally start with 10 chelations for most comers and see how they do.
Regarding neurotoxicity of DTPA. DTPA is a simple chelator, so it is pulling out metals and cations, really doing nothing else. So whereas Gd will insert itself in place of Ca at neural synapses, being a similar atomic radius cation, the ligand ofcourse cannot do that (it is an anionic molecule). If done sensibly, thoughtfully, and considering all the elements that we do when we chelate (notably Flare reaction) there should be no adverse reactions to DTPA itself. But remember nothing is 100% safe, nothing, but it seems to be as safe as things come that are administered iv, paying attention to the sentence that precedes this one.
Finally, just one injection of magnevist puts you in essentially the best category for complete recovery with properly done chelation - maybe after just 5 chelations, ands likely not more than 10. Concurrent host management may be necessary.
I have read your blogs and articles and have a simple question for you,
My calculations shows:
10 ml of Magnevist = 5 mmol Gd = .786 grams Gd = 786 mg Gd
So if 1% is retained, 1% of 10 ml of Magnevist = 1% of 786 mg=7.86 mg Gd being retained in the body.
7.86mg = 7860 mcg so DTPA IV pulls on average of 30mcg that means It would take 262 DTPA IV per 10 ml so if a patient got 3 MRIs of 20 ml most likely needs 1572 DTPA IVs. It would take 32 years if he/she does 48 DTPA IVs annually. Is my calculations make sense to you? even if I am off by factor of 2 it would still take 16 years.
Is there any fact that DTPA itself is not neurotoxin like Gd?
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