Slow, natural reduction in blood lead level after chelation therapy for lead poisoning in childhood
D. I. Moel, H. K. Sachs and M. A. Drayton
Lead poisoning is treated with chelating agents. We report the natural
decline of blood lead (Pb-B) concentration after treatment(s) (1967 to
1972) in 74 patients whose maximal Pb-B level ranged from 100 to 471
micrograms/dL (4.83 to 22.73 mumol/L). These longitudinal data (range, nine
to 17 years) disclose a predictable decrease in Pb-B levels after treatment
that is independent of the maximal Pb-B level before therapy. The
correlation between age in months and the logarithm of the Pb-B level was
significant, and the equation defined by the regression line allows one to
predict Pb-B levels at specific ages after chelation therapy. It is
important to recognize the slow, natural decline of Pb-B levels after
chelation therapy once the level is stable and below 70 micrograms/dL (3.38
mumol/L). Multiple repeated courses of calcium disodium edetate are
unlikely to influence the natural decline of the Pb-B level in asymptomatic
children.
