Edetate Calcium Disodium

( Calcium EDTA )

Pronunciation: EH-duh-tate KAL-see-uhm die-SO-dee-uhm
Class: Chelating agent

Trade Names

Calcium Disodium Versenate
- Injection 200 mg/mL

Pharmacology

Calcium is displaced by heavy metals, such as lead, to form stable EDTA complexes that are excreted in urine.

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Pharmacokinetics

Absorption

Poorly absorbed from the GI tract.

Distribution

Does not penetrate cells; distributed in the extracellular fluid with approximately 5% found in spinal fluid.

Metabolism

Not metabolized.

Elimination

The t 1/2 is 20 to 60 min. Excreted primarily by the kidneys, with about 50% excreted in 1 h and more than 95% within 24 h.

Indications and Usage

Treatment of acute and chronic lead poisoning and lead encephalopathy.

Contraindications

Anuria; active renal disease; hepatitis.

Dosage and Administration

Asymptomatic Adults

IV 5 mL ampule diluted with 250 to 500 mL normal saline or D5W. Administer dilution over 1 h or more twice daily for up to 5 days. Interrupt therapy for 2 days; follow with 5 additional days if needed (max 50 mg/kg/day).

Symptomatic Adults

IV 5 mL ampule diluted with 250 to 500 mL normal saline or D5W. Administer dilution over 2 h. Give second daily infusion 6 h or more after first.

Children and Patients With Overt or Incipient Lead Encephalopathy

IM 35 mg/kg twice daily every 8 to 12 h for 3 to 5 days; give second course no sooner than 4 days later. Procaine or lidocaine may be added (for concentration of up to 0.5%) to minimize pain on injection.

Drug Interactions

None well documented.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Genitourinary

Renal tubular necrosis.

Precautions

Monitor

Serum lead level

Document serum lead level prior to and during administration. Wait 1 h after administering dose before drawing serum lead sample.


Pregnancy

Safety not established.

Lactation

Undetermined.

Hydration

Patients may be dehydrated from vomiting. Because drug is excreted in urine, establish urine flow by IV infusion before administering first dose; then restrict IV fluid to basal water and electrolyte requirements.

Lead encephalopathy

Rapid infusion may be lethal in patients with cerebral edema, because of sudden increases in intracranial pressure. IM route is preferred.

Renal damage

Discontinue if urinalysis reveals large renal epithelial cells, increasing numbers of red blood cells in urinary sediment or greater proteinuria.

Overdosage

Symptoms

Cerebral edema, renal tubular necrosis.

Patient Information

  • Instruct patient to notify health care provider immediately if adverse reactions occur.
  • Explain rationale for strict I&O measurement and how to assist.
  • Refer to public health agency regarding potential sources of lead poisoning and assistance for family in proper removal.
  • Provide appropriate referrals for child who has learning deficits resulting from lead poisoning.
  • Teach signs of lead poisoning, including metallic taste in mouth, abdominal cramping, GI upset, decreased urine output, alteration in mentation, blue-black line along gum, paresthesia, seizures, and coma. Instruct to notify health care provider if any of these signs appear.
  • Counsel family in low-fat diet with adequate calcium, magnesium, zinc, iron, and copper to prevent binding and storage of lead in body.
  • Review follow-up schedule of appointments to monitor serum lead levels.

Copyright © 2009 Wolters Kluwer Health.

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