Used primarily in the treatment and prevention of malaria, particularly in regions where resistance to other antimalarial drugs like chloroquine has developed. It is often administered in combination with other antimalarial agents, such as artesunate, to enhance efficacy and reduce the risk of drug resistance. This combination is especially effective in treating uncomplicated Plasmodium falciparum malaria. Due to its ability to act against both the blood stage and liver stage of the parasite, it plays a role in prophylactic regimens in endemic areas. However, long-term or high-dose use is limited by potential liver toxicity and other side effects, requiring careful patient monitoring.