Penicillamine lead poisoning, chelation therapy with

Penicillamine (Cuprimine), a derivative of penicillin, is officially classified as a chelating agent that is often used in the treatment of heavy metal intoxication (e.g., lead poisoning). In addition, this drug has been used in patients with severe rheumatoid arthritis, and seems to be as effective as other DMARDs such as methotrexate, sulfasalazine, and gold therapy.68 98 Penicillamine, however, tends to be substantially more toxic than other DMARDs, and is therefore used rarely in the treatment of specific patients with rheumatoid arthritis.68... 

Chelation therapy often is begun with dimercaprol (3—4 mg/kg intramuscularly every 4—12 hours) until abdominal symptoms subside and charcoal (if given initially) is passed in the feces. Oral treatment with penicillamine then may be substituted for dimercaprol and continued for 4 days. Penicillamine is given in 4 divided doses to a maximum of 2 g/day. If symptoms recur after cessation of chelation therapy, a second course of penicillamine may be instituted. Succimer (2,3-dimercaptosuccinic acid), a derivative of dimercaprol, is efficacious in the treatment of arsenic poisoning but is FDA-approved only for lead chelation in children. 

Treatment of lead-poisoned animals usually involves the removal of ingested lead objects and application of antibiotics. For example, a captive bottlenose dolphin that had 40 lead-containing air pellets in its second stomach, as determined by radiography, was treated with 250.0 mg penicillamine/kg BW given orally three times daily for 5 days after the pellets had been removed from the stomach using an endoscope. Anemia in chimpanzees is sometimes associated with lead toxicity. In one case, a 19-year-old female chimpanzee with a history of excessive menstrual bleeding had a blood serum level of 1.03 mg Pb/L. The animal was successfully treated using oral chelation therapy 2,3-dimercaptosuccinic acid at 10.0 mg/kg BW per os for 5 days, then lO.Omg/kg BW for 2 weeks. 

Penicillamine is a chelating agent which binds copper, mercury, zinc, and lead. It has been used to treat poisoning from these chemicals and also for disorders of copper metabolism such as Wilson s disease and primary biliary cirrhosis. Penicillamine has been tried in scleroderma and arthritis. Hypersensitivity reactions are common. About 20%-30% of the patients show hypersensitivity reactions suchs as morbilliform exanthema, urticaria, purpura, anorexia, lymphadenopathy, leukopenia, and thrombocytopenia (Meyboom 1975 Balme and Huskisson 1977). More severe skin symptoms associated with penicillamine therapy are Stevens-Johnson syndrome, pemphigus, myasthenia gravis, cholestatic jaundice (Barzilai et al. 1978), nephropathy (Lange 1978) and lupus-like syndrome (Harpey et al. 1972). 

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