No

Chelating Agent

Treatment of symptomatic acute and chronic lead poisoning or for symptomatic patients with high blood lead levels; used as an aid in the diagnosis of lead poisoning; possibly useful in poisoning by zinc, manganese, and certain heavy radioisotopes

B

Severe renal disease, anuria

Potentially nephrotoxic; renal tubular acidosis and fatal nephrosis may occur, especially with high doses; EKG changes may occur during therapy; do not exceed recommended daily dose; avoid rapid I.V. infusion in the management of lead encephalopathy, may increase intracranial pressure to lethal levels. If anuria, increasing proteinuria, or hematuria occurs during therapy, discontinue calcium EDTA. Minimize nephrotoxicity by adequate hydration, establishment of good urine output, avoidance of excessive doses, and limitation of continuous administration to less than or equal to 5 days.

Percentage unknown: Anemia, anorexia, arrhythmias, arthralgia, cheilosis, chills, EKG changes, fever, GI upset, headache, hypercalcemia, hypotension, lacrimation, microscopic hematuria, mild increase in liver function tests, nasal congestion, nausea, numbness, pain at injection site following I.M. injection, paresthesia, proteinuria, renal tubular necrosis, skin lesions, sneezing, thrombophlebitis following I.V. infusion (when concentration >5 mg/mL), transient marrow suppression, tremor, vomiting, zinc deficiency

Decreased effect: Do not use simultaneously with zinc insulin preparations; do not mix in the same syringe with dimercaprol

Dilute with 0.9% sodium chloride or D₅W; physically incompatible with D₁₀W, LR, Ringer's

Calcium is displaced by divalent and trivalent heavy metals, forming a nonionizing soluble complex that is excreted in urine

Absorption: I.M., S.C.: Well absorbed

Distribution: Into extracellular fluid; minimal CSF penetration

Half-life, plasma: I.M.: 1.5 hours; I.V.: 20 minutes

Elimination: Rapidly excreted in urine as metal chelates or unchanged drug, decreased GFR decreases elimination; when administered I.V., urinary excretion of chelated lead begins in 1 hour and peak excretion of chelated lead occurs within 24-48 hours

Several regimens have been recommended:

Children: 500 mg/m²/dose, (maximum dose: 1 g) as a single dose or divided into 2 doses

Adults: 500 mg/m²/dose

Note: Urine is collected for 24 hours after first EDTA dose and analyzed for lead content; if the ratio of mcg of lead in urine to mg calcium EDTA given is >1, then test is considered positive; for convenience, an 8-hour urine collection may be done after a single 50 mg/kg I.M. (maximum dose: 1 g) or 500 mg/m² I.V. dose; a positive test occurs if the ratio of lead excretion to mg calcium EDTA >0.5-0.6.

Treatment of lead poisoning: Children and Adults (each regimen is specific for route):

Symptoms of lead encephalopathy and/or blood lead level >70 mcg/dL: Treat 5 days; give in conjunction with dimercaprol; wait a minimum of 2 days with no treatment before considering a repeat course:

I.M.: 250 mg/m²/dose every 4 hours

I.V.: 50 mg/kg/day as 24-hour continuous I.V. infusion or 1-1.5 g/m² I.V. as either an 8- to 24-hour infusion or divided into 2 doses every 12 hours

Symptomatic lead poisoning without encephalopathy or asymptomatic with blood lead level >70 mcg/dL: Treat 3-5 days; treatment with dimercaprol is recommended until the blood lead level concentration <50 mcg/dL:

I.M.: 167 mg/m² every 4 hours

I.V.: 1 g/m² as an 8- to 24-hour infusion or divided every 12 hours

Asymptomatic children with blood lead level 45-69 mcg/dL: I.V.: 25 mg/kg/day for 5 days as an 8- to 24-hour infusion or divided into 2 doses every 12 hours

Depending upon the blood lead level, additional courses may be necessary; repeat at least 2-4 days and preferably 2-4 weeks apart

Adults with lead nephropathy: An alternative dosing regimen reflecting the reduction in renal clearance is based upon the serum creatinine. Refer to the following:

Dose of Ca EDTA based on serum creatinine:

S_cr less than or equal to 2 mg/dL: 1 g/m²/day for 5 days*

S_cr 2-3 mg/dL: 500 mg/m²/day for 5 days*

S_cr 3-4 mg/dL: 500 mg/m²/dose every 48 hours for 3 doses*

S_cr >4 mg/dL: 500 mg/m²/week*

*Repeat these regimens monthly until lead excretion is reduced toward normal.

For intermittent I.V. infusion, administer the dose I.V. over at least 1 hour in asymptomatic patients, 2 hours in symptomatic patients; for I.V. continuous infusion, dilute to 2-4 mg/mL in D₅W or normal saline and infuse over at least 8 hours, usually over 12-24 hours; for I.M. injection, 1 mL of 1% procaine hydrochloride may be added to each mL of EDTA calcium to minimize pain at injection site

BUN, creatinine, urinalysis, I & O, and EKG during therapy; intravenous administration requires a cardiac monitor, blood and urine lead concentrations

If calcium EDTA is given as a continuous I.V. infusion, stop the infusion for at least 1 hour before blood is drawn for lead concentration to avoid a falsely elevated value

No information available to require special precautions

No effects or complications reported

You will most likely require frequent blood tests and monitoring during therapy. Report pain at injection/infusion site, palpitations, or difficulty urinating. You must remain supine for a period of time following treatment, change position slowly, ask for assistance if you must get up. Inform prescriber if you are pregnant. Do not breast-feed.

Injection: 200 mg/mL (5 mL)

American Academy of Pediatrics Committee on Drugs, "Treatment Guidelines for Lead Exposure in Children," Pediatrics, 1995, 96(1 Pt 1):155-60.

Moel DI and Kumar K, "Reversible Nephrotic Reactions to a Combined 2,3-Dimercapto-1-propanol and Calcium Disodium Ethylenediaminetetraacetic Acid Regimen in Asymptomatic Children With Elevated Blood Lead Levels," Pediatrics, 1982, 70(2):259-62.

Osterloh J and Becker CE, "Pharmacokinetics of CaNa₂ EDTA and Chelation of Lead in Renal Failure," Clin Pharmacol Ther, 1986, 40(6):686-93.

"Treatment Guidelines for Lead Exposure in Children. American Academy of Pediatrics Committee on Drugs," Pediatrics, 1995, 96(1 Pt 1):155-60.