PHARMACOKINETICS OF MESO-2,3-DIMERCAPTOSUCCINIC ACID IN PATIENTS WITHLEAD-POISONING AND IN HEALTHY-ADULTS

We compared the pharmacokinetics of meso-2,3-dimercaptosuccinic acid ( DMSA) in three children with lead poisoning, three adults with lead po isoning, and five healthy adult volunteers. All subjects received DMSA orally. Maximum blood concentration and time to maximum blood concent ration of total DMSA concentration were not statistically different am ong the groups. Unaltered DMSA was detected in the blood of all poison ed patients but in only one of five healthy volunteers. Elimination ha lf-life of total DMSA (parent drug plus oxidized metabolites) was long er in children with lead poisoning (3.0 +/- 0.2 hours) than in adults with lead poisoning (1.9 +/- 0.4 hours) and healthy adults (2.0 +/- 0. 2 hours). Renal clearance of total DMSA was greater in healthy adults (77.0 +/- 13.2 ml/min per square meter) than in either adults (24.7 +/ - 3.3 ml/min per square meter) or children with lead poisoning (16.6 m l/min per square meter); renal clearance of the metabolites of DMSA wa s also greater in healthy adults (64.6 +/- 10.1 ml/min per square mete r) than in either adults (35.4 +/- 8.6 ml/min per square meter) or chi ldren with lead poisoning (19.5 ml/min per square meter). The DMSA app eared to enter the erythrocytes of patients with lead poisoning to a g reater extent than in healthy adults. We conclude that renal clearance of DMSA and its metabolites may be impaired and that the distribution of DMSA in children with lead poisoning may be different from that in adults.