Hydroxychloroquine is an antimalarial drug, sold under the trade name Plaquenil , also used to reduce inflammation in the treatment of Rheumatoid arthritis (see Disease-modifying antirheumatic drugs ) and lupus . more

Hydroxychloroquine is an antimalarial drug, sold under the trade name Plaquenil , also used to reduce inflammation in the treatment of Rheumatoid arthritis (see Disease-modifying antirheumatic drugs ) and lupus .

Hydroxychloroquine is classified as an anti-malarial medication, and is one of a number of drugs which have been used for many years in the treatment of malaria. It is useful in treating systemic lupus erythematosus as well as rheumatoid arthritis and Sjögren's Syndrome (all rheumatic disorders). While hydroxychloroquine has been known for some time to decrease lysosomal pH in antigen presenting cells, its mechanism of action in inflammatory conditions has been recently elucidated and involves blocking the activation of toll-like receptors on plasmacytoid dendritic cells (PDCs). Toll-like receptor 9 (TLR 9), which recognizes DNA-containing immune complexes leads to the production of interferon and causes the dendritic cells to mature and present antigen to T cells . Hydroxychloroquine, by decreasing TLR signaling reduces the activation of dendritic cells , thus mitigating the inflammatory process. less