Daily low dose chlorproguanil is an effective alternative to daily proguanil in the prevention of P. falciparum malaria in Kenya

ABSTRACT

156 coastal schoolchildren participated in a placebo controlled trial. All the children were treated with chloroquine 25mg/kg over 3 days plus single dose pyrimethamine-sulfadoxine and then randomised to receive one of four regimens- A7.5 mg chlorproguanil daily; B 50 mg chlorproguanil weekly; C 100mg proguanil daily; D 100 mg Calcium lactate weekly. The children were followed up daily for 169 days for P.falciparum parasitaemia. Each 'terminal' event for the construction of life table; was treated with single dose pyrimethamine-sulfadoxine and the child removed from the trial. At the end of the study; 34/37 children had suffered a terminal event in the placebo group compared to 12/39 in the daily proguanil 100 mg group; 15/39 in the daily chlorproguanil 7.5 mg group and 22/40 in the weekly chlorproguanil 50 mg group. Life table analysis found a significant reduction (P is greater than 0.001) in the risk of malaria in all the chemoprophylactic groups compared to the placebo group. Daily proguanil also gave greater protection than weekly chloroproguanil (P greater than 0.05); but there was no difference between daily proguanil and daily chlorproguanil (P less than 0.1). Daily chlorproguanil 7.5 mg; has a lower cumulative dose; greater in vitro activity and increased intracellular concentration of the metabolite. Compared to proguanil and increased intracellular concentration of the metabolite. Therefore; daily proguanil has significant potential as another chealp; effective; nontoxic chemoprophylactic addition to vector avoidance measures: