CHRONIC LEAD-POISONING TREATED WITH DIMERCAPTOSUCCINIC ACID

A 54-year-old male with chronic lead poisoning was treated with 2,3-dimercaptosuccinic acid (DMSA). A daily dosage of 30 mg/kg body weight for three days and 20 mg/kg for four days resulted in a decrease of the blood-lead concentration (B-Pb) from 3.7 to 0.7-mu-mol/l; the total amount of lead excreted in the urine during the first seven 24 hr periods was 75-mu-mol. After the treatment, B-Pb slowly increased to 3.3-mu-mol/l. A second treatment was then initiated and resulted in similar changes in B-Pb. However, during the third treatment, the patient developed a mucocutaneous vesicular flare; the eruptions faded after cessation of the chelation therapy, but could be provoked by DMSA doses of 10 mg/kg and above. Despite the small number of treatment courses, the patient showed obvious mental improvement and reported less headache and improved memory. Thus,DMSA is an efficient chelator that results in a rapid, though temporary decrease in B-Pb. Although oral treatment with this chelator may be supervised from the out-patient clinic, careful monitoring for potential side effects is recommended.