Chloroquine dihydrochloride is primarily used as an antimalarial medication, effectively treating and preventing malaria caused by Plasmodium species. It works by interfering with the parasite's ability to digest hemoglobin in red blood cells, leading to its death. Beyond malaria, it has been explored for its potential in treating autoimmune diseases like rheumatoid arthritis and lupus due to its immunomodulatory properties. It reduces inflammation by inhibiting immune system activity. Additionally, it has been studied for its antiviral effects, particularly in managing certain viral infections, though its efficacy varies. In research, it is used as a lysosomotropic agent to study cellular processes involving lysosomes. Its applications are diverse, spanning therapeutic and experimental uses.