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.
Dr Neil Long BMBS FACEM FRCEM FRCPC. Emergency Physician at Kelowna hospital, British Columbia. Loves the misery of alpine climbing and working in austere environments (namely tertiary trauma centres). Supporter of FOAMed, lifelong education and trying to find that elusive peak performance.