| Item |
Information |
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Drug Groups
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approved |
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Description
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A chelating agent (chelating agents) that sequesters a variety of polyvalent cations. It is used in pharmaceutical manufacturing and as a food additive. [PubChem] |
| Indication |
For the reduction of blood levels and depot stores of lead in lead poisoning (acute and chronic) and lead encephalopathy, in both pediatric populations and adults. |
| Pharmacology |
Edetate calcium is a heavy metal chelating agent. The calcium in edetate calcium can be displaced by divalent or trivalent metals to form a stable water soluble complex that can be excreted in the urine. In theory, 1 g of edetate calcium can theoretically bind 620 mg of lead, but in reality only about 5 mg per gram is actually excreted into the urine in lead poisoned patients. In addition to chelating lead, edetate calcium also chelates and eliminates zinc from the body. Edetate calcium also binds cadmium, copper, iron and manganese, but to a much lesser extent than either lead or zinc. Edetate calcium is relatively ineffective for use in treating mercury, gold or arsenic poisoning. |
| Toxicity |
Inadvertent administration of 5 times the recommended dose, infused intravenously over a 24 hour period, to an asymptomatic 16 month old patient with a blood lead content of 56 mcg/dl did not cause any ill effects. Edetate calcium disodium can aggravate the symptoms of severe lead poisoning, therefore, most toxic effects (cerebral edema, renal tubular necrosis) appear to be associated with lead poisoning. Because of cerebral edema, a therapeutic dose may be lethal to an adult or a pediatric patient with lead encephalopathy. Higher dosage of edetate calcium disodium may produce a more severe zinc deficiency. |
| Affected Organisms |
| • |
Humans and other mammals |
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| Biotransformation |
Almost none of the compound is metabolized. |
| Absorption |
Poorly absorbed from the gastrointestinal tract. Well absorbed following intramuscular injection. |
| Half Life |
The half life of edetate calcium disodium is 20 to 60 minutes. |
| Elimination |
It is excreted primarily by the kidney, with about 50% excreted in one hour and over 95% within 24 hours.2 Almost none of the compound is metabolized. |
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