Pharmacological action This product is a compound preparation composed of dihydroartemisinin and piperaquine phosphate. Dihydroartemisinin, a derivative of artemisinin, is an active substance in vivo of artemisinin, which has a strong killing effect on plasmodium clones and can quickly kill plasmodium, thus controlling symptoms. The experiment of drug resistance cultivation shows that plasmodium is not easy to develop drug resistance to dihydroartemisinin. Pipequine phosphate is an antimalarial drug in 4-aminoquinoline, and its antimalarial effect is similar to that of chloroquine, which affects the ultrastructure of plasmodium erythrocytic merozoite, mainly swelling the food vesicle and mitochondria of trophozoite, leading to the destruction of its physiological function, thus killing plasmodium. Pipequine phosphate and chloroquine are not cross-resistant. Pharmacodynamic studies in vitro suggest that the combination of the two drugs has synergistic effect and can delay the emergence of drug resistance of plasmodium. Toxicological study of dihydroartemisinin: genotoxicity: Ames test, CHL chromosome aberration test and micronucleus test were all negative. Reproductive toxicity: it has embryotoxic effect on pregnant mice, which can increase embryo absorption in a dose-dependent manner; No teratogenic effect was observed. Pipequine phosphate: Toxicity of repeated administration: Beagle dogs were given it orally once a week,100 mg/kg * *14 weeks, or 2 mg/kg * * 26 weeks. It was found that the main toxic target organ was the liver. Genotoxicity: Ames test, chromosome analysis of bone marrow cells and sister chromatid exchange rate (SCE) test were all negative. Reproductive toxicity: no embryotoxicity and teratogenicity were found in animal experiments. The combination of dihydroartemisinin and piperaquine phosphate is toxic and has no toxic effect.