Artesunate, Artemether, Dihydroartemisinin moa and use

These artemisinin derivatives are metabolized in the food vacuole of the parasite forming toxic free radicals. Artemisinins are blood schizonticides active against P falciparum, including multidrugresistant strains. An intravenous form of artesunate is available for severe infections. However, they are now considered the first choice for chloroquine-resistant malaria in most countries. They are best used in combination with other agents. The artemisinins are the only drugs reliably effective against quinine-resistant strains. Artemisinin is derived from the qinghaosu plant, which has been used in Chinese medicine for more than 2 millennia in the treatment of fevers and malaria. Its antimalarial action involves the production of free radicals within the plasmodium food vacuole, following cleavage of the drug’s endoperoxide bridge by heme iron in parasitized erythrocytes. It is also believed to covalently bind to and damage specific malarial proteins.