Efficacy of a 3-day oral regimen of quinine in an area of northern Nigeria with low-grade resistance of Plasmodium falciparum to chloroquine and sulphadoxine-pyrimethamine.

The efficacy in vivo of a 3-day oral regimen of quinine (30 mg/kg/day) was assessed in 34 children with falciparum malaria in an area of northern Nigeria with previously documented low-grade parasite resistance to chloroquine and sulphadoxine-pyrimethamine (SDX/PYR). By day 4, all 34 children were free of parasites. Mean parasite clearance time and fever clearance time were 2.7 and 1.7 days, respectively. However, on day 14, 5 (14.7%) children were again parasitaemic and 4 of them were clinically ill. They were again treated successfully with a standard course of oral chloroquine. No adverse drug effects were recorded. Of the 34 children, 9 parasite isolates were successfully cultured in vitro. EC50 and EC99 were 14.0 and 126.0 pmol per well respectively, indicating decreased parasite sensitivity but no resistance in vitro. In conclusion, the 3-day course of quinine was found to be an effective alternative to standard chloroquine treatment in the study area.