Sodium Calcium Edetate (EDTA) is an intravenous heavy metal chelating agent.
EDTA is primarily used in the treatment of severe lead poisoning with or without lead encephalopathy or an asymptomatic/mildly symptomatic patient with a serum lead level >70 microgram/dL (3.38 micro mol/L).
EDTA is second line to succimer as a chelator and should not be used if the patient is anuric
- Commence dimercaprol (BAL) at 4 mg/kg IM every 4 hours and continue for 5 days.
- Dilute EDTA 50-75 mg/kg in 500 ml of 0.9% saline of 5% dextrose and infuse over 24 hours starting 4 hours after the first dose of dimercaprol
Symptomatic lead poisoning without encephalopathy:
- Commence dimercaprol (BAL) at 3 mg/kg IM every 4 hours and continue for 5 days.
- Dilute EDTA 25-50 mg/kg in 500 ml of 0.9% saline of 5% dextrose and infuse over 24 hours starting 4 hours after the first dose of dimercaprol
EDTA therapy is usually continued for a maximum of 5 days or in the setting of encephalopathy until the patient is clinically stable. Therapy is then interrupted for 2 to 4 days to allow redistribution of the lead prior to consideration of a further 5-day course.
Once clinically improved, chelation may be switched to oral succimer if tolerated.
- Local pain and thrombophlebitis
- Malaise, fatigue, myalgia, dermatitis, headaches, lacrimation, urinary frequency.
- Transaminase elevations
- ECG changes
- Nephrotoxicity secondary to dissociation of EDTA-metal complexes in acidic urine – reduced by ensuring adequate hydration and urinary flow 1-2ml/kg/hour.
- Bradberry S, Vale A. A comparison of sodium calcium edetate (edetate calcium disodium) and succimer (DMSA) in the treatment of inorganic lead poisoning. Clinical Toxicology 2009; 47:841-858.
- Treatment guidelines for lead exposure in children. Committee on Drugs. Pediatrics 1995; 96: 155-160.