J. Julian Chisolm

Safety and Efficacy of Meso-2,3- dimercaptosuccinic Acid (DMSA) in Children with Elevated Blood Lead Concentrations

Objective: To evaluate the safety and efficacy of meso-2,3-dimercaptosuccinic acid in the treatment of children with lead toxicity. Design: This was an open-label study in 59 children 12–65-months old, with pretreatment whole-blood lead levels of 25–66 μg/dL, who received 116, 26–28 day courses of oral dimercaptosuccinic acid, while residing either in the Pediatric Clinical Research Unit of the Johns Hopkins Hospital or in lead-safe housing during the outpatient portion of the study. Results: All, who completed the study, showed sharp decreases in blood lead concentration during therapy, but 2–3 weeks following completion of drug therapy, blood lead concentration rebounded to an average of 58% (23 μg Pb/dL of whole blood) of their average pretreatment blood lead concentration (40 μg Pb/dL of whole blood). There were no adverse reactions attributable to dimercaptosuccinic acid; however, 2 of the 59 patients were reexposed to defective lead paint and experienced sharp increases in blood lead concentration while on therapy. In one instance, the childs blood lead concentration increased from 20 to 90 μg Pb/dL whole blood in 1 week. Other unexpected events were discussed in the text. Conclusions: Dimercaptosuccinic acid is apparently safe and does mobilize lead into the urine, but not the essential metals, zinc and copper. Reexposure is always a danger; therefore, all children, while on therapy, should be monitored for their blood lead concentration at weekly intervals during and immediately after therapy. No conclusions can be drawn from this study regarding long-term beneficial effects, if any, of this drug on late neurocognitive outcome.

Soil lead abatement and children's blood lead levels in an urban setting.

OBJECTIVESnThe effect of abating soil lead was assessed among Baltimore children. The hypothesis was that a reduction of 1000 parts per million would reduce childrens blood lead levels by 0.14 to 0.29 mumol/L (3-6 micrograms/dL).nnnMETHODSnIn 2 neighborhoods (study and control), 187 children completed the protocol. In the study area, contaminated soil was replaced with clean soil.nnnRESULTSnSoil lead abatement in this study did not lower childrens blood lead.nnnCONCLUSIONSnAlthough it did not show an effect in this study, soil lead abatement may be useful in certain areas.