Introduction:
Metals play a critical role in supporting functional and structural components of the body. Metal toxicity can develop due to exposure or overloading of heavy metals. Metals interfere with the functioning of the central nervous system, liver, kidneys, and hematopoietic system. Chelating agents are used in the medical field to reduce heavy metal concentrations in blood and tissues. Chelating agents are predominantly used to reduce the concentration of iron, copper, mercury, and lead. Few chelating agents are particular to a specific metal, whereas others chelate multiple metals. However, chelating agents that target numerous metals can be harmful, lowering calcium and phosphate levels. Chelating agents can be effective and life-saving in case of heavy metal poisoning.
What Is Chelation Therapy?
Chelation therapy is a procedure that involves the removal of heavy metals from the blood. They are a standard treatment for metal poisoning. Recent studies have suggested that medical conditions like diabetes, autism, heart disease, and Alzheimer's are treated with chelation therapy for metal poisoning. Recent studies have indicated that medical conditions like diabetes, autism, heart disease, and Alzheimer's disease are treated with chelation therapy.
What Is Heavy Metal Poisoning?
A common health concern develops following exposure to sewage waste and industrial or agricultural chemicals. Contaminated food consumption or medication can also induce heavy metal poisoning. The severity of metal toxicity depends on the duration of exposure and absorption rate.
What Are the Therapeutic Chelating Agents?
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Iron Chelating Agent: The agents available are Deferoxamine, Deferasirox, and Deferiprone. These agents target only iron in the body. Deferiprone and Deferasirox are administered orally, whereas Deferoxamine is administered parenterally.
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Copper Chelating Agents: Penicillamine, Trientine, and Dimercaprol are currently used for treating Wilson disease, a condition characterized by excess copper accumulation. The agent Dimercaprol should be administered intravenously and is used for acute or advanced disease conditions. It can also reduce the concentration of arsenic and mercury in the body. Wilson disease is predominantly treated with oral administration of Penicillamine and Trientine. However, Penicillamine can lead to acute liver injury. Zinc can also be used for treating Wilson's disease, but reduce copper absorption from the diet.
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Lead Chelating Agent: Succimer, Dimercaprol (BAL), and Ethylenediaminetetraacetic acid (EDTA) are the chelating agents used. Calcium disodium EDTA can effectively treat childhood lead poisoning. Succimer is orally administered and is effective and well tolerated. Other agents require intravenous administration. In addition, the agents are helpful in mercury, cadmium, and arsenic poisoning.
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Mercury Chelating Agents: A chelating agent, sodium 2,3 dimercaptopropane 1-sulfonate, efficiently clears mercury from the body.
What Are the Prerequisites of a Good Chelating Agent?
The chelating agent must have a greater affinity to toxic heavy metals and induce less toxicity in the body. The agent must be efficient in competing with natural chelators. They must easily penetrate the cell membrane for efficient binding with metal ions. The chelating agent should form water-soluble compounds that can be rapidly expelled from the body.
What Is the Mechanism of Action of Chelation Therapy?
Chelating agents are administered orally, intravenously, or parenterally. Chelating agents are organic or inorganic compounds that bind with metal ions to form a complex ring-like structure known as chelates. Once when injected, the chelating agent circulates within the bloodstream. The agent binds with metal in the bloodstream. All the heavy metals after chelation are converted into a compound filtered by kidneys and eliminated through urine. When a chelating agent binds to toxic metals, their toxicity is reduced by shielding their biological sites with the agent.
The factor influencing the binding ability of chelating agents is pH (potential hydrogen). The pH regulates the complex formation and the compound's stability. Most chelating agents become unstable at lower pH, whereas metals form insoluble hydroxides that do not bind with chelating agents at higher pH.
What Are the Advantages of Treatment With Chelating Agents?
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They efficiently remove heavy metals like lead, arsenic, mercury, iron, copper, and nickel from blood.
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Wilson's disease can be treated with chelating agents.
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Hemochromatosis (a condition causing excessive iron absorption) can be treated with a chelating agent, and the excessive iron levels are normalized.
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In individuals with chronic kidney disease undergoing dialysis, aluminum builds up. It is removed with chelation therapy.
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Regular blood transfusion is recommended in thalassemia patients, which causes iron buildup. It is reduced by using a chelating agent.
What Medical Conditions Can Benefit From the Use of Chelating Agents?
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Heart Ailments: Chelation therapy is indicated for treating atherosclerosis. The agents bind to calcium in plaque resulting in their dislodgement and removal. However, studies performed on patients that had suffered from heart attacks did not support the notion.
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Diabetes: Chelation therapy does not help cure diabetes. But individuals with diabetes are at a higher risk for heart disease that can be treated with chelation therapy. In scientific studies conducted, it was reported that EDTA could reduce the risk of heart ailments in diabetic patients.
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Autism: Scientific studies found a link between high levels of lead in a child's teeth could lead to autism development. However, performing chelation therapy in children is found to be harmful. Animal studies have shown possibilities for cognitive impairment.
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Alzheimer's Disease: Alzheimer's disease was said to have developed from the accumulation of aluminum in the brain from pots, pans, water, food, and deodorant. The use of chelating agents was recommended for curing Alzheimer's. However, most chelating agents, except EDTA, are large and unable to cross the blood-brain barrier. Further studies require to be conducted to conclude EDTA's effectiveness.
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Parkinson's Disease: Iron builds up in the brain of individuals with Parkinson's disease. However, the relationship between iron buildup and Parkinson's disease is not fully understood. Hence, the efficacy of the chelating agent cannot be determined.
Why Is Chelation Therapy Dangerous?
Chelating agents used in the medical field are powerful and can produce mild or severe side effects. A burning sensation at the injection site is the side effect most frequently reported. Other less intense side effects include fever, headache, nausea, and vomiting.
Low blood pressure, anemia, cardiac arrhythmias, seizures, brain damage, vitamin and mineral deficiencies, permanent kidney and liver damage, and fatal hypocalcemia or anaphylactic reactions are potentially dangerous side effects.
Conclusion:
Individuals suffering from heavy metal poisoning must be treated with therapeutic chelating agents. At present chelating agents are approved for the treatment of metal poisoning only. There are claims that chelating agents are beneficial for managing medical ailments. The unnecessary use of a chelating agent can lead to severe adverse effects. Chelating agents are administered only when the benefits outweigh the negatives.
