Intravenous quinine therapy of hospitalized children with Plasmodium falciparum malaria in Kinshasa, Zaire.

To examine the clinical and parasitologic efficacy of quinine, we studied 34 children (7 months-13 years old) with severe or moderately severe Plasmodium falciparum infections. Quinine 10 mg/kg every 8 hr for 3 days was administered, initially by intravenous infusion of quinine formate followed by oral quinine dihydrochloride when tolerated. Thirty-three of the 34 patients were clinically well and had negative malaria smears 7 days after the initiation of therapy; 1 child, who presented in coma, died 29 hr after enrollment. The mean fever clearance time was 44.1 hr, and the mean parasite clearance time was 59.6 hr. A mean peak quinine level of 9.7 ppm was attained after the second dose of quinine, and the minimum concentration was maintained at 5-7 ppm during the 2nd and 3rd hospital days. In vitro testing was conducted with parasites from 10 patients: 9 isolates were resistant to chloroquine, and inhibition of schizont development with quinine occurred at a concentration of 8-32 pmol/well.