Red cell and plasma
quinine-
quinidine, and
quinine concentrations in children with uncomplicated
falciparum malaria who were treated with a combination of
quinine/
quinidine/
cinchonine (combined
drug) and
quinine alone, respectively, were measured, using the extraction fluorescence method. The cure rates obtained with the high dose regimen of the combined
drug (100%) were significantly higher than in the low dose regimen group (37.5%) (p less than 0.05), and the
quinine regimen produced a 50% cure rate. Similar mild and transient ECG effects were noted in both the combined
drug group and the
quinine group. In patients treated with the combined
drug,
quinine-
quinidine concentrations in both red cell and plasma of the high dose regimen group were significantly higher than those in the low dose regimen group (p less than 0.001, p less than 0.001). In
quinine-treated patients, red cell
quinine concentration in those with RII failure was significantly lower than that in patients with cure or RI failure (p less than 0.05). Both red cell and plasma levels of
quinine-
quinidine were higher than
quinine levels. The red cell:plasma
quinine-
quinidine concentration ratios rose steadily to the high level from day 3 to day 6, while the ratio of
quinine alone fluctuated around the low level and then gradually fell. The evidence suggests that red cell
drug concentrations are more closely related to the outcome of treatment than to plasma concentrations and that the combined
drug may be very useful for treatment of multi-
drug-resistant P. falciparum
infections. Further study is needed.