What is artesunate, and what is it used for?

Artesunate is a medication administered intravenously to treat serious malaria, a disease with high fevers, shaking chills, and flu-like illness, in adults and children.

Malaria is caused by microscopic unicellular parasites belonging to the Plasmodium species, and the disease caused by Plasmodium falciparum is the type most likely to result in severe infections that can even lead to death, if not promptly treated.

Malaria is transmitted by the bite of infective female Anopheles mosquitos. Malarial parasites grow and multiply in the human liver first and then get into red blood cells and multiply further. The parasites grow digesting the hemoglobin inside red blood cells, eventually rupturing them and releasing daughter parasites that invade other blood cells. The blood stage parasites cause malarial symptoms in humans.

Artesunate is a semisynthetic drug derived from artemisinin, a compound obtained from the plant sweet wormwood, Artemisia annua. Artesunate is active against the blood-stage asexual adult parasites and germ cells (gametocytes) of Plasmodium species, including chloroquine resistant strains, but not against hypnozoites, the liver stage forms of P. vivax and P. ovale, which can remain dormant and invade the blood after months or even years.

Artesunate is rapidly metabolized in the blood into its active metabolite dihydroartemisinin (DHA). Artesunate, like other artemisinins, contains an endoperoxide bridge, a structural feature that is activated by the heme iron in the hemoglobin. This generates free radicals (reactive oxygen species) which cause oxidative stress, make ultrastructural changes and inhibit the synthesis of proteins and DNA in the parasites, preventing their growth and survival.