Cycloguanil Pamoate in the Treatment and Suppression of Malaria in the Gambia, West Africa

Abstract

The repository antimalarial properties of single doses of cycloguanil pamoate were tested in hyperendemic field conditions in the Gambia, West Africa. The first subgroup of treated subjects developed pain, tenderness, induration, and swelling at the injection site in high incidence, and sterile abscess formation occurred in 27%. Change of injection site to one less closely associated with adipose tissue greatly reduced the incidence of local reaction in subjects treated subsequently. No signs indicative of systemic toxicity were detected in treated or control subjects and haemoglobin concentrations in the former tended to improve after dosage. Asexual parasitaemia existed in 65% of treated subjects befor dosage. At day 7 post therapy all were trophozoite-free, though gametocytaemia persisted. Before injection 63% of control subjects were similarly parasitized and by day 7 55% were still infected. Chemoprophylaxis following cycloguanil administration was of substantially greater duration than would have been expected to follow a single dose of any known antimalarial. However, compared with results obtained in American volunteers its duration was disappointingly short. It is suggested that the extreme muscular activity of Gambian subjects may have increased rates of drug absorption and excretion. The occurrence of strains of plasmodia resistant to cycloguanil pyrimethamine, or proguanil was not observed during the trial. The absence of signs of systemic toxicity following cycloguanil administration indicates that further field trials should be undertaken at higher dosage levels. © 1966, British Medical Journal Publishing Group. All rights reserved.