Efficacy of oral meso-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 mumol/L (45 micrograms/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 mumol/L (20 to 60 micrograms/dl) selected for DMSA use. Reasons for DMSA use included BPb concentration > 2.17 mumol/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 mumol/L (31 micrograms/dl), and group 2 (n = 7) had a mean BPb concentration of 2.41 (51 micrograms/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 than and greater than 2.17 mumol/L.