Chelation therapy is the administration of chelating agents to remove heavy metals from the body. For the most common forms of heavy metal intoxication, those involving lead, arsenic or mercury, the standard of care in the USA dictates the use of DMSA. Other chelating agents, such as DMPS and alpha lipoic acid (ALA), are used in conventional and alternative medicine. Chelation (from Greek χηλή, chelè, meaning claw) is the process of reversible binding (complexation) of a ligand - the chelant, chelator, chelating agent, sequestering agent, or complexing agent - to a metal ion, forming a metal complex, the chelate. ... A heavy metal is any of a number of higher atomic weight elements, which has the properties of a metallic substance at room temperature. ... This article is about the metal. ... General Name, Symbol, Number arsenic, As, 33 Chemical series metalloids Group, Period, Block 15, 4, p Appearance metallic gray Standard atomic weight 74. ... General Name, Symbol, Number mercury, Hg, 80 Chemical series transition metals Group, Period, Block 12, 6, d Appearance silvery Standard atomic weight 200. ... In tort law, the standard of care is the degree of prudence and caution required of an individual who is under a duty of care. ... DMSA or dimercaptosuccinic acid is a chelating agent. ... Wikipedia does not yet have an article with this exact name. ... Chemical structure of 2,3-dimercapto-1-propanesulfonic acid 2,3-Dimercapto-1-propanesulfonic acid or DMPS is a chelating agent that forms complexes with various heavy metals. ... Lipoic acid, also known as α-lipoic acid (alpha lipoic acid) or thioctic acid, has formula C8H14S2O2 and systematic name 5-(1,2-dithiolan-3-yl)pentanoic acid. ... For the chemical substances known as medicines, see medication. ...

Discovery and history in medicine

Chelating agents were introduced into medicine as a result of the use of poison gas in World War I. The first widely used chelating agent, the organic dithiol compound dimercaprol, also named British Anti-Lewisite, or BAL, was used as an antidote to the arsenic based poison gas, Lewisite. It binds the arsenic in Lewisite with two strong chemical bonds with the SH groups ("mercaptans"), forming a water soluble compound that entered the bloodstream, allowing it to be removed from the body by the kidneys and liver. BAL had severe side-effects. A poison gas attack in World War I. The use of poison gas was a major military innovation of the First World War. ... British Anti Lewisite, often referred to by its acronym BAL, is a compound developed by the British biochemists of Oxford University during World War II . ... British Anti Lewisite, often referred to by its acronym BAL, is a compound developed by the British biochemists of Oxford University during World War II . ... Lewisite is a chemical compound from a chemical family called arsines. ... In chemistry, thiols (formerly known as mercaptans) are those compounds which contain the thiol group -SH attached to a carbon atom. ...

After World War II, a large number of navy personnel suffered from lead poisoning as a result of their jobs repainting the hulls of navy ships. At this time, the medical use of EDTA as a lead chelating agent was introduced. Unlike BAL, it is a synthetic amino-acid; in particular, it contains no mercaptans. While EDTA had some uncomfortable side effects, they were nowhere near as severe as BAL. EDTA is a widely-used acronym for the chemical compound ethylenediamine tetraacetic acid (and many other names, see table). ...

In the 1960s, BAL was modified into DMSA, a related dithiol with far fewer side effects. DMSA quickly replaced both BAL and EDTA, becoming the US Standard of Care for the treatment of lead, arsenic and mercury poisoning, which it remains today. DMSA or dimercaptosuccinic acid is a chelating agent. ... In tort law, the standard of care is the degree of prudence and caution required of an individual who is under a duty of care. ...

Research in the former Soviet Union led to the introduction of DMPS, another dithiol, as a mercury chelating agent. The Soviets also introduced ALA, which is transformed by the body into the dithiol dihydrolipoic acid, a mercury and arsenic chelating agent. DMPS has experimental status in the US FDA, while ALA is a common nutritional supplement. Chemical structure of 2,3-dimercapto-1-propanesulfonic acid 2,3-Dimercapto-1-propanesulfonic acid or DMPS is a chelating agent that forms complexes with various heavy metals. ... Lipoic acid is the trivial name for 6,8-dithiooctanoic acid, ( HSCH2CH2CH(SH)C4H8COOH ) which is regarded as a coenzyme in the oxoglutarate dehydrogenase complex of the citric acid cycle. ...

Other chelating agents have been discovered. They all function by making several chemical bonds with metal ions, thus rendering them much less chemically reactive. The resulting complex is water soluble, allowing it to enter the bloodstream and be excreted harmlessly.

Medical use

Two molecules of deferasirox, an orally administered chelator, binding iron. Deferasirox is used in the treatment of transfusional iron overload in people with thalassemia.

Chelation therapy is used as a treatment for acute mercury, iron (including in cases of thalassemia), arsenic, lead, uranium, plutonium and other forms of toxic metal poisoning. The chelating agent may be administered intravenously, intramuscularly, or orally, depending on the agent and the type of poisoning. Image File history File links Size of this preview: 800 × 480 pixelsFull resolution (1000 × 600 pixel, file size: 147 KB, MIME type: image/png) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Size of this preview: 800 × 480 pixelsFull resolution (1000 × 600 pixel, file size: 147 KB, MIME type: image/png) File historyClick on a date/time to view the file as it appeared at that time. ... Deferasirox (marketed as Exjade®) is an oral iron chelator. ... For other uses, see Iron (disambiguation). ... Transfusion hemosiderosis is the accumulation of iron, mainly in the liver, in patients who receive frequent blood transfusions (such as those with thalassemia or aplastic anemia). ... Thalassemia (British spelling, thalassaemia) is an inherited autosomal recessive blood disease. ... For other uses, see Iron (disambiguation). ... Thalassemia (British spelling, thalassaemia) is an inherited autosomal recessive blood disease. ... General Name, Symbol, Number arsenic, As, 33 Chemical series metalloids Group, Period, Block 15, 4, p Appearance metallic gray Standard atomic weight 74. ... Lead poisoning is a medical condition, also known as saturnism, plumbism or painters colic, caused by increased blood lead levels. ... General Name, symbol, number uranium, U, 92 Chemical series actinides Group, period, block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Standard atomic weight 238. ... General Name, Symbol, Number plutonium, Pu, 94 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery white Standard atomic weight (244) g·mol−1 Electron configuration [Rn] 5f6 7s2 Electrons per shell 2, 8, 18, 32, 24, 8, 2 Physical properties Phase solid Density (near r. ... Toxic metals are metals that form poisonous soluble compounds and have no biological role, i. ...

One example of successful chelation therapy is the case of Harold McCluskey, a nuclear worker who became very badly contaminated internally with americium in 1976. He was treated with diethylene triamine pentaacetic acid (DTPA) over many years, removing 41 MBq (1.1 mCi) of americium from his body. His death, 11 years later, was from unrelated causes. Harold R. McCluskey was a chemical operator at the Hanford nuclear weapons plant located in Washington state who is known for having survived exposure to the highest dose of radiation in 1976. ... General Name, Symbol, Number americium, Am, 95 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery white Atomic mass (243) g/mol Electron configuration [Rn] 5f7 7s2 Electrons per shell 2, 8, 18, 32, 25, 8, 2 Physical properties Phase solid Density (near r. ... The becquerel (symbol Bq) is the SI derived unit of radioactivity, defined as the activity of a quantity of radioactive material in which one nucleus decays per second. ... The curie (symbol Ci) is a former unit of radioactivity, defined as 3. ...

Several chelating agents are available, having different affinities for different metals. Common chelating agents include:

• Alpha lipoic acid (ALA)
• Aminophenoxyethane-tetraacetic acid (BAPTA)
• Defarasirox
• Deferoxamine
• Diethylene triamine pentaacetic acid (DTPA)
• Dimercaprol (BAL)
• Dimercapto-propane sulfonate (DMPS)
• Dimercaptosuccinic acid (DMSA)
• Ethylenediamine tetraacetic acid (calcium disodium versante) (CaNa₂-EDTA)
• Ethylene glycol tetraacetic acid (EGTA)
• D-penicillamine

Lipoic acid, also known as α-lipoic acid (alpha lipoic acid) or thioctic acid, has formula C8H14S2O2 and systematic name 5-(1,2-dithiolan-3-yl)pentanoic acid. ... Categories: Stub | Amines | Aromatic compounds | Carboxylic acids | Ethers ... Defarasirox (marketed as Exjade) is an oral iron chelator. ... Deferoxamine, otherwise known as desferrioxamine or desferal, is a chelating agent used to remove excess iron from the body. ... Diethylene triamine pentaacetic acid is an elongated version of EDTA. Categories: | | ... British Anti Lewisite, often referred to by its acronym BAL, is a compound developed by the British biochemists of Oxford University during World War II . ... 2,3-Dimercapto-1-propanesulfonic acid (abbreviated DMPS) or its sodium salt (known as Unithiol) are chelating agents that form complexes with various heavy metals. ... DMSA or dimercaptosuccinic acid is a chelating agent. ... EDTA is a widely-used acronym for the chemical compound ethylenediamine tetraacetic acid (and many other names, see table). ... EGTA is the chemical compound ethylene glycol tetraacetic acid, a chelating agent that is related to the better known EDTA, but with a much higher affinity for calcium than for magnesium ions. ... Penicillamine is a pharmaceutical of the chelator class. ...

Use in alternative medicine

Alternative medicine uses chelation therapy in the treatment of heart disease,^[1][2], in cases of unrecognized but claimed heavy metal poisoning,^{[citation needed]} and in the treatment of autistic patients. Alternative medicine is defined as any of various systems of healing or treating disease (as chiropractic, homeopathy, or faith healing) not included in the traditional medical curricula taught in the United States and Britain.[1] Complementary medicine is defined as any of the practices (as acupuncture) of alternative medicine accepted...

Heavy metal poisoning

Alternative practitioners claim to recognize extensive environmental exposures to heavy metals, such as through contact with treated lumber or pesticides. Many of their patients claim to have been exposed to mercury through their dental amalgam fillings. Others claim that they, or their children, have become exposed to mercury from thimerosal, an ethyl-mercury compound used as a preservative in some vaccines. It is the nonoccupational nature of these cases which distinguishes chelation therapy in alternative practice from that in conventional medicine.^{[citation needed]} Treated lumber is lumber pressure treated with fire retardant chemicals, to reduce chance of fire and smoke. ... An amalgam is an alloy of mercury. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Ethylmercury (sometimes ethyl mercury) is a cation composed of an ethyl group and a mercury atom; its chemical formula is C2H5Hg+. The term ethylmercury is sometimes used as a generic term to describe organomercury compounds which include ethylmercury such as ethylmercury chloride and ethylmercury urea. ...

Today, DMSA is alternative practitioners' chelating agent of choice.^{[citation needed]} They also make use of DMPS and ALA, as well as the conventionally obsolete lead chelating agent EDTA.^{[citation needed]}

Folklore has given rise to the use of various high sulfur foods, including onions, garlic, green foods and seaweeds, as "chelating agents".^{[citation needed]} Sulfur supplements like MSM or NAC have also been used. These are not actually chelating agents, as chelators involve multiple bonds to the metal ion and these foods and supplements involve compounds that are only monothiols.

Cilantro (coriander) has also been used,^[3] and is present in numerous alternative medications like PCA-Rx, Metal-Free (both of which also contain ALA) and NDF. Although cilantro was widely described as a chelator of lead, mercury or other heavy metals in internet literature,^[4][5] and is often used as such, there is a paucity of research about such claims.^[6] Dr. Garry Gordon, one of the developers of intravenous chelation in the 1950s, has tested patients for heavy metals before and after substantial cilantro intake but has found no increase of increased mercury or lead excretion in urine or fecal tests.^[7] He has, however, claimed increased excretion when calcium disodium EDTA is combined with pectin and garlic.^[8] Binomial name Coriandrum sativum Coriander (Coriandrum sativum) is an annual herb commonly used in Middle Eastern, Mediterranean, Indian, Latin American and Southeast Asian cooking. ... Chelation (from Greek χηλή, chelè, meaning claw) is the process of reversible binding (complexation) of a ligand - the chelant, chelator, chelating agent, sequestering agent, or complexing agent - to a metal ion, forming a metal complex, the chelate. ...

Heart disease

Some alternative practitioners use chelation to treat hardening of the arteries. The original theory behind calcium chelation therapy was that EDTA forms a complex with the calcium in the walls of arteries. Drawbacks with this theory include EDTA's inability to penetrate the cell walls in the arteries and therefore inability to access to the calcium, EDTA binding preferentially to other metals, and calcium posing minimal arterial danger in comparison to cholesterol and other deposits. A number of dangers have been associated with the therapy including hypocalcaemia, decreased blood coagulation ability (perhaps hypocalcaemia related), and the risk of leaching of necessary trace metals. Atherosclerosis is a disease affecting arterial blood vessels. ... Synthesis of copper(II)-tetraphenylporphine, a metal complex, from tetraphenylporphine and copper(II) acetate monohydrate. ... For other uses, see Calcium (disambiguation). ... Section of an artery For other uses, see Artery (disambiguation). ... In medicine, hypocalcemia is the presence of low serum calcium levels in the blood, usually taken as less than 2. ... This article is about the clotting of blood. ... Leaching is the process of extracting a substance from a solid by dissolving it in a liquid. ... Trace metals are metals in extremely small quantities, almost at the molecular level, that reside in or are present in animal and plant cells and tissue. ...

The safety and efficacy of EDTA chelation therapy as a treatment for coronary artery disease are being assessed by NCCAM in a five-year study which began in 2002. ^[9][10]

Some alternative practitioners believe intravenous chelation therapy "reverses and slows the progression of atherosclerosis and other age-related and degenerative diseases",^[1] such as coronary artery disease and macular degeneration. Coronary heart disease (CHD), also called coronary artery disease (CAD) and atherosclerotic heart disease, is the end result of the accumulation of atheromatous plaques within the walls of the arteries that supply the myocardium (the muscle of the heart). ... Listen to this article ( info) in media player in browser This audio file was created from an article revision dated 2005-07-19, and may not reflect subsequent edits to the article. ...

Autism

Some chelation advocates claim that autism might be caused or aggravated by heavy metal poisoning and might be ameliorated by chelation therapy,^{[citations needed]} but this is controversial, and there is little evidence from the scientific community to support this hypothesis. Autism is a brain development disorder characterized by impairments in social interaction and communication, and restricted and repetitive behavior, all exhibited before a child is three years old. ...

Controversy

The efficacy, safety, and much of the theory behind these alternative practices are disputed by the medical community. In 2001, researchers at the University of Calgary reported that cardiac patients receiving chelation therapy fared no better than those who received placebo treatment.^[11] For other uses, see Placebo (disambiguation). ...

In 2003, the Supreme Court of Missouri, in State Board of Registration for the Healing Arts v. McDonagh, 123 S.W.3d 146, overturned a decision of the State Board of Registration sanctioning a doctor who used chelation therapy for the treatment of heart disease. The Court held that the therapy was not harming patients, and the standard for determining repeated negligence in using an alternative therapy such as chelation is not whether it is popular or commonly accepted by the medical community, but rather whether heart specialists would consider its use to be reasonable.

In 1998, the U.S. Federal Trade Commission charged that the web site of The American College for Advancement in Medicine and a brochure they published had made false or unsubstantiated claims. In December 1998, the FTC announced that it had secured a consent agreement barring ACAM from making unsubstantiated advertising claims that chelation therapy is effective against atherosclerosis or any other disease of the circulatory system.^[12]

Prevalence

The American College for Advancement in Medicine (ACAM), a private corporation which promotes chelation therapy, claims that 800,000 patient visits for chelation therapy, with an average of forty visits per patient, were made in the United States in 1997.^[13] A May 2004 survey by the National Center for Complementary and Alternative Medicine (NCCAM) estimated that 0.1%, plus or minus 0.02% of the adult US population had used chelation therapy at some point in their life. The National Center for Complementary and Alternative Medicine or NCCAM, a division of the National Institutes of Health within the Department of Health and Human Services of the United States federal government, was established in October, 1991, as the Office of Alternative Medicine, which was re-established as the NCCAM... Motto: (Out Of Many, One) (traditional) In God We Trust (1956 to date) Anthem: The Star-Spangled Banner Capital Washington D.C. Largest city New York City None at federal level (English de facto) Government Federal constitutional republic  - President George Walker Bush (R)  - Vice President Dick Cheney (R) Independence from...

Side effects and safety concerns

Side effects can include headaches, skin irritation, nausea or stomach upset, diarrhea, extreme fatigue, cramps, joint pain, feeling faint, and in rare cases (0.02%) fever.^[14] Safety concerns include kidney toxicity.^[15]

Roy E. Kerry has been charged with involuntary manslaughter following the 2005 death of a five year old autistic boy.^[16]

In August 2005, an autistic boy went into cardiac arrest fifty minutes after an infusion of acidic Endrate and died with hypocalcemia. The initial coroner's report ruled the death accidental.^[17] Dr. Mary Jean Brown, chief of the Lead Poisoning Prevention Branch of the Centers for Disease Control and Prevention, said that the child died because he was given the wrong chelation agent.^[18] In medicine, hypocalcaemia is the presence of less than a total calcium of 2. ... The Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, is recognized as the leading United States agency for protecting the public health and safety of people. ...

References

External links

• garynull.com "Chelation Therapy: The Controversial Medical Marvel" by Gary Null, Ph.D. and Luanne Pennesi, RN, BSN (extensively researched study with 50 citations) Accessed May 26, 2007
• Your-Doctor.com - 'Quack Therapies: Chelation Therapy' (discusses use of chelation therapy in conventional medicine and the hazards of chelation therapy by alternative practitioners)
• Quackwatch "Chelation Therapy: Unproven Claims and Unsound Theories" by Sam Green
• GenerationRescue.org - Parent-led advocacy group promoting use of chelation therapy as a cure for autism
• Gordon Research Garry Gordon, father of chelation therapy's web site for doctors.

Pervasive developmental disorders