Studies on the efficiency of chloroquine and chloroguanide as antimalarials: I. as suppressants

Chloroquine (Aralen) and chloroguanide (Paludrine) were tried as suppressants in two different malarious localities in the Philippines for 39 to 40 weeks. The drugs were given under strict supervision in single weekly doses to two groups of subjects and those who developed overt malaria were given therapeutic doses of the respective drugs. Control groups maintained in both localities received sodium bicarbonate as a placebo and those exhibiting overt attacks were treated with quinine sulfate. Test and control subjects who had overt malaria were continued on their respective weekly drugs after a course of treatment as mentioned above. Intensive vector control measures were instituted within and around the localities starting two months before the cessation of suppressive treatment in order to stop transmission, and the number of subjects developing malaria thereafter was recorded for at least 14 weeksThe following observations were made: 1. Among 125 subjects given 0.50 Gm. chloroquine diphosphate once weekly for 39 to 40 weeks, 13 cases were suppressed, but 2 came down with overt malaria during the period of suppressive treatment2. Among 104 subjects given 0.20 Gm. chlorguanide once weekly for 39 to 40 weeks, 13 cases were suppressed, but 17 came down with overt malaria during the period of suppressive treatment3. Among 106 subjects given 0.60 Gm. sodium bicarbonate as a placebo once weekly for 39 to 40 weeks, 54 developed overt malaria4. Eight subjects with P. falciparum either at the onset or during the period of suppression with chloroquine did not exhibit gametocytes at any of the weekly examinations conducted during the 39 weeks of suppressive treatment. Chlorguanide appeared to be ineffective against vivax and falciparum gametocytes5. Among 125 subjects given 0.50 Gm. chloroquine diphosphate once weekly for 39 to 40 weeks, 2 had nausea and vomiting, 1 had vertigo, and 1 had flatulence and the desire to stool soon after taking the drug. These untoward effects were mild, temporary, and did not require withdrawal of the drugIt was shown that with the dosage regimen employed, the suppressive activity of chloroquine was greater than that of chlorguanide. It is possible, however, that with increased dosage chlorguanide may prove to be an efficient suppressantThe response of the infections to chloroquine and chlorguanide, particularly to the latter, was not the same in the two localities, suggesting the presence of different strains of plasmodia in the country. The possibility of the introduction of foreign strains into the Philippines through seeded American and Japanese soldiers during World War II is advanced. (Author)

Untoward effects of quinacrine hydrochloride as observed in 302,206 malaria cases

Observation study was made on 302,206 Filipino malaria patients who were given therapeutic doses of quinacrine hydrochloride (Atabrine). Of the 302,206 cases, 82.46% had vivax malaria and 17.54% had falciparum malaria. Two hundred twenty cases showed one or more untoward effect of the drug. Distribution of the 340 untoward effects observed in these subjects were presented. These untoward effects were temporary in nature and disappeared from one to eight days after the drug was discontinuedSelected untoward effects of drugs included the following: manic excitement, talkativeness, insomnia, depression, delusions, hallucinations, absent-mindedness and toxic psychoses.(Author)