Human Studies with the Chelating Agents, DMPS and DMSA

Meso-2,3-dimercaptosuccinic acid (DMSA) is bound to plasma albumin in humans and appears to be excreted in the urine as the DMSA-cysteine mixed disulfide. The pharmacokinetics of DMSA have been determined after its administration to humans po. For the blood, the tmaxand tl/2 were 3.0 h + 0.45 SE and 3.2 h + 0.56 SE, respectively. The Cmax was 26.2 μM + 4.7 SE. To determine whether dental amalgams influence the human body burden of mercury, we gave volunteers the sodium salt of 2,3-dimer-captopropane-1-sulfonic acid (DMPS). The diameters of dental amalgams of the subjects were determined to obtain the amalgam score. Administration of 300 mg DMPS by mouth increased the mean urinary mercury excretion of subjects over a 9 h period. There was a positive correlation between the amount of mercury excreted and the amalgam score. DMPS might be useful for increasing the urinary excretion of mercury and thus increasing the significance and reliability of this measure of mercury exposure. DMSA analogs have been desig...