The present investigation was performed to determine the effect of 14-day
oral administration of meso-2.3-dimercaptosuccinic
acid (
DMSA) on the urinary
mercury excretion and the potential reduction of blood and plasma
mercury concentrations, and also to relate these effects to possible decrease of symptoms, allegedly associated with amalgam fillings. Twenty subjects, relating their symptoms to
mercury from amalgam fillings, received 20 mg/kg
DMSA or placebo for 14 days. Their symptoms and mood states were recorded during the study and at a check-up 3 months later. Interpretation was based on intra-individual differences.
DMSA-treatment resulted in an average increase in urinary
mercury excretion by 65% and a decrease in blood
mercury levels of 0.04 microgram/L/day. At the check-up after 3 months, urinary
mercury excretion had returned to the pre-treatment level. No treatment effect of
DMSA was apparent on subjective symptoms and mood state. One statistically significant treatment effect was noted-a decrease in
fatigue-inertia in the
DMSA-group-but there was no demonstrable correlation with increased urinary excretion or decreased blood concentration of
mercury. Three subjects showed hypersensitive reactions, probably
DMSA-specific, at the end of the treatment period. This placebo-controlled study provides no scientific support for diagnostic or therapeutic administration of
DMSA for symptoms allegedly associated with chronic
mercury exposition from
dental amalgam fillings.