The relative effectiveness of some chelating agents as antidotes in acute cadmium poisoning.

An examination has been made of the relative effectiveness of three chelating agents in reducing lethality in acute cadmium poisoning. The chelating agents used were sodium 2,3 dimercaptosulfonate (DMPS), N-Acetyl d,1 penicillamine (NAPA), and 2,3 dimercaptosuccinic acid (DMSA). For cadmium acetate administered ip at a level of 16.9 mg/kg, the oral administration of the chelating agents at a 20:1 mole ratio in three doses subsequent to the cadmium acetate at 20 minutes, 90 minutes, and 210 minutes resulted in a significant enhancement of the survival rate for all three compounds. At this level none of the control animals survived beyond 2 days. On the basis of the experiments carried out here the survival rates decreased in the order sodium 2,3 dimercaptopropane-sulfonate greater than 2,3 dimercaptosuccinic acid greater than N-Acetyl d,l penicillamine. In a study of the effect of the mole ratio of the chelating agent sodium 2,3 dimercaptopropanesulfonate to cadmium acetate on the survival rate, it was found that the survival rate attained a maximum for values between 20 and 60 and dropped off at both higher and lower values. It was also found that for at least one set of conditions, younger animals were better able to survive the administration of cadmium acetate and the antidote than older animals.