EFFICACY OF ORAL MESE-2,3-DIMERCAPTOSUCCINIC ACID THERAPY FOR LOW-LEVEL CHILDHOOD PLUMBISM

Objective: To compare the response to oral meso-2, 3-dimercaptosuccinic acid (DMSA) treatment in children with an initial blood lead (BPb) concentration less than versus more than 2.17 mu mol/L (45 mu g/dl). Design: Retrospective cohort study. Setting: Regional referral lead treatment program in an urban children's hospital. Patients: Thirty consecutive children, median age 34 months (range, 5 to 161 months), with an initial BPb concentration 0.97 to 2.90 mu mol/L (20 to 60 mu g/dl) selected for DMSA use. Reasons for DMSA use included BPb concentration > 2.17 mu mol/L (11 children), complications with penicillamine therapy (11), chronic renal failure (1), and compassionate use (7). All patients received required environmental hazard reductions before drug administration. Results: Group 1 (n = 23) had a mean BPb concentration of 1.50 mu mol/L (31 mu g/ dl), and group 2 (n = 7) had a mean BPb concentration of 2.41 (51 mu g/dl). Sixteen patients (70%) in group 1 and five patients (71%) in group 2 had had previous chelation therapy (p value not significant). No significant difference was found in the mean percentage of the reduction of BPb concentration during treatment of group 1 (60%) versus group 2 (58%). The mean BPb concentration in group 1 rebounded to 70% of pretreatment values by mean day 41; the BPb Concentration in group 2 rebounded to 69% by day 37 (p value not significant). Prior chelation therapy did not result in a significant difference in either the percentage reduction of BPb concentration or the percentage of rebound BPb. Conclusion: DMSA is equally effective in acutely lowering BPb concentration in children with BPb concentrations less then and greater than 2.17 mu mol/L.