Artesunate is an antimalarial drug that is used for the treatment of severe malaria. However, its effectiveness as a prophylactic agent is not well-established. According to Drug Patent Watch [1], there are no patents for the use of artesunate as a prophylactic agent. The Centers for Disease Control and Prevention (CDC) [2] recommends the use of other antimalarial drugs, such as atovaquone-proguanil, doxycycline, or mefloquine, for malaria prophylaxis. These drugs have been extensively studied and are proven to be effective in preventing malaria.

A study published in the Journal of Travel Medicine [3] compared the efficacy of artesunate with that of mefloquine for malaria prophylaxis. The study found that mefloquine was significantly more effective than artesunate in preventing malaria. The authors concluded that artesunate cannot be recommended as a prophylactic agent for malaria.

In conclusion, while artesunate is a potent antimalarial drug, its effectiveness as a prophylactic agent is not well-established. Other antimalarial drugs, such as atovaquone-proguanil, doxycycline, or mefloquine, are recommended for malaria prophylaxis. Therefore, individuals traveling to areas with a high risk of malaria should consult with their healthcare provider to determine the most appropriate prophylactic agent for their needs.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/ARTESUNATE
[2] https://www.cdc.gov/malaria/diagnosis_treatment/artesunate.html
[3] https://pubmed.ncbi.nlm.nih.gov/22122444/