Safety and efficacy of meso-2,3-dimercaptosuccinic acid (DMSA) in children with elevated blood lead concentrations.
Level 4 - case-series / case-control
Uncontrolled open-label interventional study without a parallel control group.
PubMed 10930052 · doi:10.1081/clt-100100945
What was done
An open-label trial evaluated oral meso-2,3-dimercaptosuccinic acid (DMSA) in 59 children aged 12-65 months with pretreatment whole-blood lead levels of 25-66 microg/dL. Participants received 116 courses (26-28 days each) of oral DMSA while residing in a pediatric clinical research unit or lead-safe housing. Blood lead concentrations and adverse events were monitored.
What was found
Blood lead concentration decreased sharply during therapy in all completing patients. Two to three weeks after completing treatment, blood lead concentration rebounded to an average of 58% (23 microg Pb/dL) of the average baseline level (40 microg Pb/dL). DMSA mobilized lead into urine without mobilizing zinc or copper. There were no adverse reactions attributable to DMSA, but two patients experienced environmental lead re-exposure during therapy (one child's blood lead rose from 20 to 90 microg/dL in 1 week).
Why it matters
This study shows that oral DMSA selectively clears lead without depleting essential minerals, but post-treatment rebound is common and environmental re-exposure can rapidly reverse gains.
Limits
The study lacked a randomized control group, had a small sample size (n = 59), and did not assess long-term neurocognitive or developmental outcomes.
Cited by
- supports DMSA is an FDA-approved drug for chelation that binds heavy metals for urinary excretion.