Hydroxychloroquine is an aminoquinoline that is chloroquine in which one of the N-ethyl groups is hydroxylated at position 2. An antimalarial with properties similar to chloroquine that acts against erythrocytic forms of malarial parasites, it is mainly used as the sulfate salt for the treatment of lupus erythematosus, rheumatoid arthritis, and light-sensitive skin eruptions. It has a role as an antimalarial, an antirheumatic drug, a dermatologic drug and an anticoronaviral agent. It is an aminoquinoline, an organochlorine compound, a primary alcohol, a secondary amino compound and a tertiary amino compound. It is functionally related to a chloroquine. It is a conjugate base of a hydroxychloroquine(2+).