Recent advance in the therapy of metal poisonings with chelating agents

1 A survey is given of the use of chelating agents in the treatment of metal poisonings. 1 The complexing agents in established clinical use are the polyaminopolycarboxylic acid EDTA (ethylenediamine tetraacetate) and the thiols BAL (2, 3-dimercaptopropanol) and D-penicillamine. Desferrioxamine is useful in the treatment of iron overloading. 2 The theoretical foundation of the metal-ligand interaction and some general principles of value in the search for new metal antidotes are outlined. 3 Recent research has shown that 2, 3-dimercaptosuccinic acid (DMS) and 2, 3-dimercaptopropane-1-sulphonate (DMPS) are effective in mercury and arsenic poisonings. 4 DMS and DMPS are of significantly lower toxicity than BAL, and they can be administered orally or intravenously. 5 A particularly low toxicity of DMS is reported from clinical and experimental studies, and this agent may be useful against several metal poisonings including mercury, lead and gold.