THERAPY AND PREVENTION OF LEAD POISON-ING WITH CALCIUM VERSENATE

Abstract

Experiments on the effectiveness of Ca EDTA upon lead poisoning were undertaken, on dogs and lead workers.1. In the animal experiments the following conclusion were reached.a. The parenteral administration of Ca EDTA changed the distribution of lead in arterial blood, and plasma lead was increased. This is thought to come from the red corpuscles in which the greatest portion of lead in the blood was found when lead absorption occurs, and also from the extravascular tissues.b. Decrease of A/G ratio was not prevented by the administration of the drug, although the symptoms, including anemia, were kept normal. This indicates that the decrease of A/G ratio appears in the earlier stage of lead poisoning, with the exception of coproporphyrinuria, as has beenn stated previously.2. Clinical and prophylactic use of the drug yielded the following results.a. Intravenous therapy did not increase the lead concentration in the blood but the urinary lead showed its highest level in the urine after three hours administration.b. Higher urinary lead excretion by oral administration was obscrved in only a few patients in contrast with the results seen by intravenous injection. This indicates that the absorption from the intenstine is very low, following the oral administration.c. Oral administration (which was extended over a period of more than six months) for the purpose of preventing chronic, potential lead poisoning, was successful in decreasing both the blood lead and urine lead quantity, in preventing appearance of the symptoms, and in improving anemia.d. Further study is necessary to determine a proper, daily, oral dosage.