Metal excretion and magnesium retention in patients with intermittent claudication treated with intravenous disodium EDTA.

Sixty patients with intermittent claudication participated in a double-blind placebo-controlled trial of 20 courses of intravenous chelation therapy with 3 g of disodium EDTA vs placebo during 5-9 weeks. After the first infusion, the 24-h urinary excretion of lead and zinc was approximately 25-fold higher in the EDTA-treated group; relative differences for copper and calcium were smaller. Urinary magnesium excretion in the EDTA-treated group was one-third less than in the control group. After the treatment period, the blood lead concentration had decreased by approximately 73% and the serum zinc concentration by approximately 34%; other changes in blood concentrations were negligible. The loss of essential minerals and the possible redistribution of lead in the body may constitute a disadvantage that should be taken into account in repeated intravenous EDTA treatment.