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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