Excess of Lead from human body can be removed by using which of the following chelating agents?

EDTA

The correct answer is option 4. EDTA.

Lead poisoning is a serious condition that can cause a range of health problems, particularly in the nervous system. The body cannot easily eliminate lead on its own, so chelation therapy is often used to remove lead from the bloodstream and tissues. Chelating agents are compounds that bind to heavy metals like lead, forming a stable complex that can be excreted from the body, typically through urine.

Overview of Chelating Agents:

1. D-Penicillamine:

Primary Use: D-Penicillamine is mainly used for treating Wilson's disease, which involves an excess of copper in the body. It can also be used for treating rheumatoid arthritis.

Mechanism: It works by binding to copper, forming a complex that can be excreted in urine.

Effectiveness for Lead: Although D-Penicillamine has some chelating properties and can bind to various metals, it is not the most effective agent for treating lead poisoning. It is not typically used as the first-line treatment for lead detoxification.

2. DMG (Dimethylglyoxime):

Primary Use: DMG is primarily used as an analytical reagent for detecting nickel and palladium in laboratory tests.

Mechanism: It forms a complex with these metals, allowing for their detection in qualitative analysis.

Effectiveness for Lead: DMG is not used as a therapeutic agent for treating heavy metal poisoning in humans. It is strictly a laboratory reagent and has no clinical application in chelation therapy for lead.

3. Desferrioxamine B (Desferrioxamine):

Primary Use: Desferrioxamine is primarily used to treat iron overload, particularly in conditions like thalassemia and hemochromatosis, where excess iron accumulates in the body.

Mechanism: It chelates excess iron, allowing it to be excreted from the body, particularly in urine.

Effectiveness for Lead: While Desferrioxamine can bind to lead, it is not the preferred chelating agent for lead. Its clinical use is focused on iron chelation, and it is not commonly used in the treatment of lead poisoning.

4. EDTA (Ethylenediaminetetraacetic Acid):

Primary Use: EDTA is the most effective and widely used chelating agent for treating lead poisoning.

Mechanism: EDTA works by binding to lead ions in the bloodstream. The complex formed between EDTA and lead is stable and soluble, allowing the lead to be excreted through the kidneys. Specifically, Calcium disodium EDTA (CaNa₂EDTA) is used in clinical settings because it replaces lead ions with calcium, reducing the risk of depleting calcium from the body.

Administration: EDTA is usually administered intravenously in cases of severe lead poisoning. This method allows for quick action and efficient removal of lead from the body.

Effectiveness for Lead: EDTA is highly effective in reducing blood lead levels and is the preferred treatment for both acute and chronic lead poisoning. It is well-established in clinical protocols for detoxifying the body of lead.

Conclusion: EDTA is the most effective and appropriate chelating agent for removing excess lead from the human body, making option 4 the correct answer.