[Pharmacodynamics of dihydroartemisinine against Plasmodium berghei in mice]

Dihydroartemisinine (DHA) is a derivative of qinghaosu(artemisine), which is an antimalarial drug. DHA was given to mice inoculated with Plasmodium berhgei ANKA strain by intramuscular injection. Within proper dose range, the dose-effect and time-effect curves of DHA against the malaria can be described by y = 4.9960 + 2.9536 x and y = 7.2654 - 0.3414 t, respectively, where y is the estimated value of parasitemia suppressing rate in probit; x is log dose; t is the period since drug administration im. Accordingly, the ED50 = 1.00 +/- 0.13 mg/kg and the time of half-effect was 6.6 h, when the dose was 5.0 mg/kg im. The elimination rate constant of the effective dose in vivo was 0.2662h-1 with a half-life of 2.6 h.