Studies on antibilharzial drugs. II. Effect of 5 drugs on the toxicity and therapeutic activity of tartar emetic.

Acute toxicity experiment consisted of one single intraperitoneal injection, while subacute toxicity experiment consisted of one injection daily for 14 days, of tartar emetic and a subsequent 3-day holding period. The mortality of mice from tartar emetic was observed after concomitant injections of 5 testing drugs (procaine-HCl, sodium phenyl acetate, sodium α α'-dimercaptoadipate, sodium mercaptosuccinate and sodium thiosulfate). The effective detoxicants were mixed up with tartar emetic and then injected intraperitoneally, once daily for 14 days, to infected mice. The mice were killed after a holding period of another 14 days. Basing on the average number of worms remained in each mouse, the effects of detoxicants on the antibilharzial activity of tartar emetic were compared. The results were as follows: (1) In mice the acute and subacute LD_(50) after intraperitoneal injection of tartar emetic were found to be 38 and 35 mg/kg/day respectively. (2) The mortality of mice from tartar emetic could be markedly reduced by simultaneous injection of procaine, sodium phenyl acetate, sodium α α'-dimercaptoadipate and sodium mercaptosuccinate, while sodium thiosulfate did not afford any protection. (3) Procaine, sodium phenyl acetate, sodium α α'-dimercaptoadipate and sodium mercaptosuccinate did not decrease the therapeutic. activity of tartar emetic, and, moreover, procaine could significantly augment its therapeutic activity against schistosomiasis japonica.