The in vivo drug response of 96 patients with falciparum malaria was studied to chloroquine, amodiaquine or the combination of sulfadoxine and pyrimethamine, in Imperatriz, State of Maranhão, Brasil. The patients were randomly assigned to the three study groups and followed for seven days. Better results were obtained with the association sulfadoxine-pyrimethamine, although no statistically significant differences were observed. The need of continous surveillance of P. falciparum drug resistance in areas of high levels of transmission is emphasised.
Malaria; Chemotherapy; Resistance to drugs; Amazon basin