The treatment of acute lead encephalopathy has not changed much in the last 20 years.9- 11 The mainstay of treatment is chelation therapy, which is frequently limited by toxic reactions.10- 12 The pharmacological action of BAL has proven useful for chelating several heavy metals, including lead.10- 12 As BAL must be administered by deep intramuscular injection every 4 hours, treatment is painful and often difficult to adhere to, especially in children. Most of the other adverse effects tend to be dose limiting, but do not contraindicate the use of BAL unless the patient has an allergy to peanut oil (the diluent in which BAL is prepared) or is glucose-6-phosphate dehydrogenase–deficient.10- 12 Calcium disodium EDTA (ethylenediaminetetraacetic acid) has been available for the treatment of lead poisoning for more than 50 years. Initial use revealed salt-specific problems.12 The current salt form (calcium disodium EDTA) is now the specific agent approved for use in treating lead intoxication, but it still binds other metal ions including zinc, copper, and manganese.12 Its major limiting toxicity is a dose- and infusion rate–related nephrotoxicity.12 In an effort to minimize toxic effects, we used a 5-day continuous intravenous infusion for our patient. In 1968, Chisolm10 recommended the use of BAL and calcium disodium EDTA together for the treatment of moderate to severe lead poisoning and found the combination to be superior to either agent alone in lowering the blood lead concentration. In 1992, O'Connor11 also studied the combination of calcium disodium EDTA and BAL, corroborating the results found by Chisolm in 1968 that gave us the current recommendations for the treatment of acute lead encephalopathy.9- 11 Most current treatment regimens for children who are symptomatic for chronic lead poisoning or who are asymptomatic but have blood lead concentrations greater than 3.38 µmol/L (>70 µg/dL) recommend removal of the child from the source of lead and inpatient treatment with parenteral drug therapy.9 Patients who are asymptomatic with blood lead concentrations between 2.17 and 3.33 µmol/L (45 and 69 µg/dL) generally receive chronic outpatient treatments or are admitted for parenteral drug therapy with calcium disodium EDTA.9 In 1991, meso-2,3-dimercaptosuccinic acid, or succimer, was added to the treatment options for mild to moderate lead poisoning (2.17-3.33 µmol/L [45-69 µg/dL]), representing the only new agent for the treatment of lead poisoning in more than 30 years.9,12 Besunder et al13 and Graziano et al14 studied meso-2,3 dimercaptosuccinic acid in the short-term treatment of patients with low to moderate blood lead concentrations and found it both efficacious and safe. Cory-Slechta15 used meso-2,3-dimercaptosuccinic acid for long-term treatment in rats and also found it to be both safe and effective.15 She does note that it may be effective as an adjunct treatment with calcium disodium EDTA to further reduce total body lead burden.