Comparisons of antidotal efficacy of sodium diethyldithiocarbamate, D-penicillamine and triethylenetetramine upon acute toxicity of nickel carbonyl in rats.

Sodium diethyldithiocarbamate, D-penicillamine, and triethylene-tetramine were administered to rats by im injection in dosages equivalent to 0.6 times their respective LD50 values in order to compare their relative effectiveness in prevention of death caused by exposure for 15 min to inhalation of nickel carbonyl (1.4 or 4.2 mg Ni (CO)4/liter of air). When the three drugs were administered to groups of rats at 10 min before or after the exposure to nickel carbonyl, sodium diethyldithiocarbamate was the most effective antidote. In contrast, then the drugs were administered at 6 hr after exposure to nickel carbonyl, D-penicillamine was the most effective antidote. Based upon the combined results of 4 sets of experiments, sodium diethyldithiocarbamate and D-penicillamine were significantly more effective than triethylenetetramine. The authors recommend that sodium diethyldithio-carbamate should remain the chelating agent of choice for therapy of nickel carbonyl poisoning. If sodium diethyldithiocarbamate is not available or if its use is contraindicated, D-penicillamine might be considered as an alternative chelating agent.