In vivo and in vitro responses to quinine and quinidine of Plasmodium falciparum.
A total of 66 Thai children with uncomplicated falciparum malaria were treated orally with regimens of either quinine or quinidine. Radical cures were observed in 85% (28 of 33) of the children who received quinine and in 88% (29 out of 33) of those who received quinidine. Treatment failures in both groups were RI responses.The mean trough level of quinidine (10 mumol/l) was about 2.5-times less than that of quinine (25 mumol/l). The electrocardiograms of the two treatment groups differed significantly in that there was an acute prolongation of the QT(c) interval in 56% of those who received quinidine compared with 21.0% of those given quinine. In vitro assays of the pretreatment drug susceptibilities of the isolates of Plasmodium falciparum indicated that the mean minimum inhibitory concentration (MIC) for quinidine (1.44 mumol/l) was about half that for quinine (3.02 mumol/l). Although both drugs are equally effective, quinine is recommended for treatment of multidrug-resistant malaria in paediatric patients, primarily because of the cardiac effects produced by quinidine.
D000818:Animals; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008288:Malaria / Q000188:drug therapy*; D008297:Male; D010963:Plasmodium falciparum / Q000187:drug effects*; D011446:Prospective Studies; D011802:Quinidine / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use*; D011803:Quinine / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use*; D011897:Random Allocation
D011803:Quinine; D011802:Quinidine