dmsa

Good link on DMSA


http://www.dmsa-chelation.info/

How DMSA works
In healthy individuals, approximately 20 percent of an oral dose of DMSA is absorbed from the gastrointestinal tract. Ninety-five percent of the DMSA that makes it to the bloodstream is bound to albumin. One of the sulfhydryls in DMSA binds to a cysteine residue on albumin, leaving the other S-H available to chelate metals. In healthy fasting men, 90 percent of the DMSA recovered in the urine was found to be mixed disulfides (where DMSA is attached to one or two cysteine molecules), and 10 percent was free unchanged DMSA. No mixed disulfides were found in the blood. It is thought these disulfides are formed as albumin releases DMSA in the kidneys.

There is no question that DMSA is more readily absorbed when it is taken on an empty stomach. However, some people experience gastric upset when they take DMSA apart from food, and that is more likely to occur in children. Therefore, caution and flexibility are required in regard to this.

DMSA Treatment in Lead Toxicity
DMSA has been used since the 1950s as an antidote for lead poisoning in Russia, Japan, and the Peoples Republic of China. DMSA has been shown in recent studies to be a safe and effective chelator of lead, reducing blood levels significantly. At a dose of 10 mg/kg for five days in adult males, DMSA lowered blood lead levels 35.5 percent; a more aggressive approach utilizing a 30 mg/kg dose lowered blood lead 72.5 percent. Clinical symptoms and biochemical indices of lead toxicity also improved.

Co-administration of N-acetylcysteine (NAC) and Vitamin C have been found to enhance the effectiveness of DMSA at eliminating lead from the body.

A suggested protocol for lead toxicity is to identify and remove the environmental exposure, and use DMSA 10 mg/kg three times a day for the first five days, followed by 14 days at 10 mg/kg twice a day.

DMSA Treatment in Mercury Toxicity
In the USA, DMSA was first reported by Friedheim to promote mercury excretion. He reported on experiments with mice in 1975, noting DMSA's low toxicity and favorable efficacy compared to other compounds, such as BAL and D-penicillamine. Since that time, numerous animal and human studies have shown DMSA administration increases urinary mercury excretion and reduces blood and tissue mercury concentration.

In a comparison study of chelating agents, eleven construction workers with acute mercury poisoning acute mercury poisoning were treated with either DMSA or N-acetyl-D,L-penicillamine (NAP), another sulfhydryl-containing metal chelator. DMSA treatment resulted in greater urinary excretion of mercury than NAP.

In a study of single-dose, DMSA-induced urinary excretion in occupationally-poisoned workers, a significant increase in urinary mercury excretion was noted, especially in the first 24 hours. Mercury excretion was greatest in the first eight hours after oral DMSA administration.

After methylmercuric chloride administration in rats, DMSA, DMPS, and NAP were studied for their ability to remove mercury from blood and tissue. DMSA was the most effective at removing mercury from the blood, liver, brain, spleen, lungs, large intestine, skeletal muscle, and bone. DMPS was more effective at removing mercury from the kidneys.

Chelation of Mercury from the Brain
In rats, following intravenous administration of methyl mercury, DMSA was found to be the most efficient chelator for brain mercury.

In another animal study, DMSA was given four days after methyl mercury injection in mice, and continued for eight days. DMSA removed two-thirds of the brain mercury deposits, NAP removed approximately one-half, while DMPS did not remove significant amounts of mercury from the brain.

Mercury Diagnostic and Treatment Protocol
Hair analysis is an inexpensive and valuable tool for evaluating prior mercury exposure. However, there has been some controversy about the accuracy of laboratory results in hair analysis.

An effective way to evaluate mercury toxicity quantitatively is to determine the amount of mercury excreted in the urine after a challenge dose of DMSA. A baseline 24-hour urine is collected before the challenge, then again on day three of a three-day dosing of 200 mg three times a day.

The therapeutic dosage of DMSA for mercury toxicity is not well defined in the literature. Doses as high as 30 mg/kg per day have been used, with no serious side effects noted. One DMSA treatment protocol suggests 10 mg/kg day taken in divided doses for three days. The patient then discontinues taking DMSA for 14 days, then takes it again for 3 days. Five to 10 treatment cycles may be necessary. Another protocol suggests 500 mg per day on an empty stomach, every other day for a minimum of five weeks. For very sensitive patients, 250 mg per day, every other day may be necessary, with an increase to 500 mg after two to three weeks, for a total of five weeks of therapy. More studies need to be done to define optimal dosing strategies for this substance. Be aware that sulfhydryl compounds in DMSA will make urine very smelly. Patients should be warned about that so that they won't be surprised.

Some advocate the use of hydrolyzed whey protein as an adjunct to DMSA because it contains a lot of cysteine and cysteine residues which can be of benefit while using DMSA. Cysteine is the rate-limiting step in glutathione production, which is necessary for fecal heavy metal excretion and hepato-protection. Whey also contains branched-chain amino acids which occupy transport sites at the blood-brain barrier, effectively keeping bound metals from being re-deposited in the brain. Supplemental dosing of N-acetylcysteine, 500 mg three times per day, can also be helpful.

A multi-mineral supplement is a must when taking DMSA, and it should also be taken between cycles and for some time after treatment is ended. This is so because, besides heavy metals, DMSA also chelates and eliminates good minerals, such as zinc and magnesium.

DMSA for the brain
The organic mercury species with greatest toxicity are methylmercury compounds, which have a high affinity for the brain and nervous system. No other substance has been found to absorb better and cross the blood brain barrier and remove mercury from the brain more effectively than DMSA. DMPS is much less effective. DMPS is also 3 times more toxic than DMSA, based on its LD-50 (the dose at which 50 percent of laboratory animals die). Animal studies show DMSA to be almost 3 times more effective than DMPS in removing brain mercury. DMSA has the added advantage that it is taken by mouth in capsule form, whereas DMPS must be given by injection.


Please note, this is from a site that is selling DMSA, so even though I'm using it with good results, please do your own research. But it's a place to start. Barium is a heavy metal, like cadnium (in gold solder, so it's an issue for my husband and I because of occupational exposure) so it should work for barium exposure as well.


EDIT: Additional article, also from a company blurb that sells the product:


http://www.vrp.com/articles.aspx?page=LIST&ProdID=1697&zType=2

Julie