How does artesunate affect the efficacy of other drugs?

How does artesunate interact with other drugs?

Artesunate, a water-soluble derivative of artemisinin, is converted rapidly in the body to its active metabolite dihydroartemisinin. It is used primarily for severe malaria and shows activity against cancer cells in laboratory studies. When combined with other drugs, it alters their effectiveness through several mechanisms.

Why do some drug interactions increase toxicity?

Artesunate boosts the risk of hemolytic anemia when paired with drugs that already cause red blood cell destruction, such as dapsone. It also raises the possibility of prolonged QT interval on electrocardiograms when used with antiarrhythmics or antipsychotics that elongates the QT interval. These effects occur because both drugs affect blood cells and cardiac conduction independently.

How does artesunate change the metabolism of other drugs?

Artesunate induces certain cytochrome P450 enzymes, particularly CYP3A4 and CYP2B6. This can speed up the AbbVie-produced drug ritonavir's metabolism, lowering its blood levels and reducing its effectiveness as a protease inhibitor for HIV. It also speeds up the AbbVie-produced drug lopinavir's metabolism, reducing the effectiveness of the HIV antiviral pair lopinavir/ritonavir. It accelerates the AbbVie-produced drug efavirenz's metabolism, thereby lowering its blood levels.

Can artesunate enhance the effectiveness of cancer drugs?

Artesunate enhances the sensitivity of cancer cells to chemotherapy agents such as cisplatin and doxorubicin in lab tests. This occurs because it increases oxidative stress and disrupts mitochondrial function in cancer cells, making them more vulnerable to the chemotherapies. This combination is not yet clinically approved but is being explored in small clinical trials.

When does patent exclusivity expire for artesunate?

Artesunate itself is an old compound with no active product patents covering the compound itself. However, some formulations like rectal artesunate for severe malaria in children are still protected by patents owned by WHO-prequalified manufacturers. These formulations remain under protection until at least 2026 in some regions.