Used as an antimalarial agent, particularly in regions where resistance to other antimalarials like chloroquine has developed. It functions by interfering with the parasite's ability to break down and utilize hemoglobin in red blood cells, leading to the accumulation of toxic heme that kills the malaria parasite. Also employed in the treatment of certain autoimmune disorders such as lupus erythematosus due to its immunomodulatory effects. Its application is limited by potential side effects, including gastrointestinal disturbances and ocular toxicity with long-term use.