Activities of Amodiaquine, Artesunate, and Artesunate-Amodiaquine against Asexual- and Sexual-Stage Parasites in Falciparum Malaria in Children

ABSTRACTThe activities of amodiaquine, artesunate, and artesunate-amodiaquine against asexual- and sexual-stage parasites were evaluated in 360 Nigerian children with uncomplicated Plasmodium falciparummalaria randomized to the standard dose regimens of the three drugs/combination. Clinical recovery from illness occurred in all children. There were no significant differences in fever clearance times. Patients treated with artesunate or artesunate-amodiaquine had significantly shorter parasite clearance times (1.4 ± 0.5 days or 1.4 ± 0.6 days versus 3.2 ± 2.3 days, P= 0.0001) and lower gametocyte carriage rates (3.3 or 1.7% versus 11.7%, P= 0.001) than those treated with amodiaquine alone. Gametocytemia was detected in 62 patients (11.7% before treatment and 5.6% after treatment). The pretreatment gametocyte sex ratio, which was female biased, increased significantly during the course of treatment with amodiaquine but not with artesunate and artesunate-amodiaquine. These results suggest that artesunate and artesunate-amodiaquine reduce gametocyte carriage and may reduce transmissibility in P. falciparummalaria by accelerating asexual clearance and influencing gametocyte sex ratio.