On the Toxicity of Some Organic Antimonial Drugs Used for the Treatment of Kala-Azar

are widespread. Some indication of the value of antimony is the fact that without treatment the death rate from kala-azar is over 90 per cent, whereas with treatment in Indian kalaazar it is reduced to below 10 per cent. Although tartar emetic was found of value in the treatment of kala-azar, its considerable toxic effects made it imperative to obtain other derivatives which should be better tolerated while having, if possible, a greater therapeutic effect. The introduction of a pentavalent organic antimony derivative, urea stibamine, by Brahmachari in the year 1922, was an important development in the history of chemotherapy of kala-azar. Urea stibamine is obtained by the interaction of p-aminophenylstibinic acid with urea. The exact chemical nature of this important drug is still not definitely known. Since its discovery, attempts have been made by various workers in different laboratories to produce an ideal drug for the treatment of kala-azar. Most of the organoantimonials that have had clinical trials haye been derivatives of p-aminophenylstibinic acid. Besides urea stibamine, neostibosan (the diethylamine salt of p-aminophenylstibinic acid) has also proved effective in the treatment of kala-azar. t ?