Iodochloroxyquinoline (Vioform,N.N.R.) as an Amebacide in Macaques. ∗

Abstract

In a previous study of a series of halogenated oxyquinoline derivatives, iodochloroxyquinoline (vioform, N.N.R.) was shown to be an effective balanticide in guinea pigs, with relatively low toxicity on repeated administration to monkeys. 1 The soluble hydrochloride of the basic ether of this compound was found to kill amoebae in vitro in high dilutions. On this basis we began to investigate the amebacidal effect of vioform, N.N.R., in macaques naturally infested with Entamoeba histolytica. Similar studies were made by Kessel 2 with sodium iodoxyquinoline sulphonate (“yatren” or chinofon, N.N.R.) in monkeys. Doses of from one-half to 2 gm. were given daily, by this worker, to 4 macaques for 4 weeks. Two animals died in the second week of treatment when given 2 gm. of this drug daily. The 2 surviving monkeys received one-half gm. daily for 4 weeks and their stools remained negative for Entamoeba histolytica for a 3 months period. 3

Dobell 4 has demonstrated the effectiveness of emetine bismuth iodide in monkey amebiasis. Twelve mgm. per kilo orally given daily for about a week cleared 4 of 5 macaques of Entamoeba histolytica. Four of these animals, however, exhibited signs of emetine toxicity during the course of this rather vigorous treatment. This fact was not sufficiently emphasized by Dobell but should be remembered before attempting to apply these results to human therapy. His suggestion “that macaques…. be utilized…. in place of men in future chemotherapeutic experiments” is certainly timely.