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Table 1 Chemical properties and pharmacologic basis of the chelating agents used in lead and arsenic poisoning

From: Treatment of lead and arsenic poisoning in anuric patients – a case report and narrative review of the literature

  BAL DMPS CaNa2EDTA DMSA
Amendable to EBP + ++ +++ + / -
Molecular Weight (Dalton) 124 228 374 182
Chelate-Pb Complex MW (Dalton) a 331
(455 if ratio is 2:1) [3]
434 540 389
Chelate-Ars Complex MW (Dalton) a 199
(323 if ratio is 2:1) [3]
303
(803 if ratio is 3:2) [4]
Cannot chelate arsenic [16] 257
Administration Route IM in peanut oil medium PO, IV IV, IP, IM PO
Distribution Lipophilic Hydrophilic Hydrophilic Hydrophilic
Volume of Distribution High 0.16 L/kg [4] 0.21 L/kg [17] 0.4 L/kg b [18]
Protein Binding n/a 62.5% [19] 11 – 19% [20] 95% [21]
Excretion Renal (Major) Renal (46 – 59%)
Biliary (extent undetermined)
Renal (Major) Renal (Major)
LD50 (mmol/kg) 1.48 c [16] 6.53 c [16] 16.4 [5] 13.73 c [16]
Contraindications Peanut allergies, hepatic dysfunction, methylmercury poisoning None in acute lead or arsenic toxicity None in acute lead toxicity None in acute lead or arsenic toxicity
Adverse Effects Nausea, vomiting, headache, hypertension, pain and/or sterile abscess at injection site, haemolysis in G6PD-deficiency, chelation of essential metals in prolonged use Allergic reaction, nausea, vomiting, Steven-Johnson syndrome (rare) Fatigue, headache, mild AST/ALT elevations, nephrotoxicity, chelation of essential metals in prolonged use Nausea, vomiting, diarrhoea, mild AST/ALT elevations, Fever, rash, reversible neutropenia (rare), chelation of essential metals in prolonged use
  1. MW molecular weight, IM intramuscular, IV intravenous, PO oral, IP intraperitoneal, Pb lead, Ars arsenic
  2. a: the ratio of chelate-metal complex is presumably 1:1 as data is limited; n/a: not available
  3. b: based on primates
  4. c: based on mice IP