Treatment of falciparum malaria in Vietnamese children: the need for combination therapy and optimized dosage regimens

To assess the in vivo sensitivity of Plasmodium falciparum to mefloquine an d artesunate in a hyperendemic area of southern Viet Nam, we studied 41 chi ldren and 21 adults from a remote commune who had uncomplicated falciparum malaria without previous treatment. Patients were randomly allocated to art esunate (4 mg/kg on day 0 and 2 mg/kg on days 1-4) or mefloquine (10 mg/kg followed by 5 mg/kg at 6 h). Serial assessments were performed over 28 days . Of 31 patients allocated artesunate, nine (29%) redeveloped parasitaemia during follow-up compared with 23% (seven of 30) who received mefloquine. O f the 41 children, 15 (37%) had recrudescence/re-infection compared with on ly one of 20 adults (5%; p < 0.001). Significantly more children than adult s failed on mefloquine treatment (37% vs 0%; p = 0.021) and one case showed RIII resistance. There was no significant difference in the case of artesu nate. In regression analysis, parasitaemia was an independent predictor of recrudescence/re-infection after mefloquine (p = 0.02). These data support the use of combination therapy such as artesunate plus mefloquine for falci parum malaria in a hyperendemic area of Viet Nam. Primarily because of thei r greater parasite densities, children should be given higher doses of mefl oquine (e.g. 25 mg/kg).