It is also 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 increase lysosomal p H 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). Plaquenil prevebt lupus flare Hydroxychloroquine effects on taste Mechanism of Action of Hydroxychloroquine as an Antirheumatic Drug By Robert I. Fox The antimalarial agents chloroquine and hydroxychloroquine have been used widely for the treatment of rheumatoid arthritis and systemic lupus erythematosus. These compounds lead to improvement of clinical and laboratory parameters. Chloroquine and hydroxychloroquine are drugs derived from the quinoline molecule. Both are used as antimalarial blood schizonticides, and hydroxychloroquine is also frequently used as an antirheumatic. Their mechanism of action is not entirely understood. However, despite their varying therapeutic dosage and toxicity. New light has been shed on the mechanisms of action of both colchicine and hydroxychloroquine. Colchicine has multiple effects including disruption of the innate immunity by suppressing the NALP3 inflammasome-driven caspase-1 activation of interleukin 1ß processing and release, and L-selectin expression on neutrophils 5. Classically, colchicine is known to inhibit microtubule polymerization, which results in impaired lysosomal transport along microtubules. Hydroxychloroquine, by decreasing TLR signaling, reduces the activation of dendritic cells thus mitigating the inflammatory process. 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 usmle mechanism of action Hydroxychloroquine Information for Providers AIDSinfo, Chloroquine and hydroxychloroquine – Knowledge for medical. Plaquenil costfor genericIs plaquenil used to treat osteoarthritisChloroquine tablet prescriptionPharmacological classification of hydroxychloroquine First, hydroxychloroquine has an additive in vitro anti-HIV effect to that of zidovudine. 37 Second, chloroquine exerts in vitro an additive anti-HIV-1 effect on the combinations of hydroxyurea plus didanosine or hydroxyurea plus zidovudine in T-cell lines, monocytes, and primary T-cells.2, 38. Effects of chloroquine on viral infections an old drug.. Hydroxychloroquine and Colchicine Induced Myopathy The Journal of.. Recommendations on Screening for Chloroquine and Hydroxychloroquine.. Hydroxychloroquine Plaquenil is considered a disease-modifying anti-rheumatic drug DMARD. It can decrease the pain and swelling of arthritis. It may prevent joint damage and reduce the risk of long-term disability. Hydroxychloroquine is in a class of medications that was first used to prevent and treat malaria. Disease-modifying antirheumatic drugs DMARDs are a group of medications commonly used in people with rheumatoid arthritis. Some of these drugs are also used in treating other conditions such as ankylosing spondylitis, psoriatic arthritis, and systemic lupus erythematosus. They work to decrease pain and inflammation. A study of about 200 patients with a history of hydroxychloroquine retinopathy, including 36 Asian patients, found that the pericentral pattern occurred in half the Asian patients but only 2% of the white patients. 31 The mechanism for this finding is unclear, but because pericentral retinopathy spares the macula, it can be missed using standard screening methods.