THE PROTECTIVE ACTION OF BAL IN EXPERIMENTAL ANTIMONY POISONING

¹ Laboratory of Experimental Therapeutics of the U.S. Public Health Service and The Johns Hopkins School of Hygiene, Baltimore 5, Maryland

1. On single intravenous injection, the lethal (LD₉₅) levels of Fuadin, tartar emetic, Anthiomaline and p-methylphenylstibonic acid were found to be 150, 15, 12 and 10 mg./kg., respectively.

2. BAL had a definite protective action in rabbits given otherwise lethal doses of these antimonials. With all four compounds, injections of BAL at 10 to 15 mg./kg. administered 4 times at 4-hour intervals saved approximately half the animals.

3. As has been previously shown to be the case with arsenicals, the protective action of BAL in experimental antimony poisoning was, in 3 of the 4 compounds tested, associated with and probably due to a significantly increased urinary excretion of antimony. The hourly rate of excretion increased 2- to 8-fold in rabbits given a single injection of BAL at 20 mg./kg., 28 hours after the injection of the antimonial at the LD₅₀ level. This favorable effect on excretion lasted for 2 to 4 hours, indicating the need for repeated injections at approximately 4-hour intervals when BAL is used therapeutically in cases of antimony poisoning.