Hydroxychloroquine is an aminoquinoline with antimalarial, anti-inflammatory, and antiviral activities. It is active against the chloroquine-sensitive NF54 and D6 strains of P. falciparum (IC50s = 16.3 and 15 nM, respectively) but has decreased activity against chloroquine-resistant P. falciparum strains (IC50s = 422.7-1,735.3 nM). Hydroxychloroquine inhibits production of IL-22, IL-17A, and IL-6 induced by phorbol 12-myristate 13-acetate (TPA; ) and ionomycin in peripheral blood mononuclear cells (PBMCs) isolated from healthy individuals or patients with systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA). It inhibits accumulation of sequestosome-1 (SQSTM1) puncta, a marker of autophagy, in mouse embryonic fibroblasts (MEFs) in a concentration-dependent manner. Hydroxychloroquine reduces viral titers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the culture supernatant of infected Vero E6 cells but does not reduce SARS-CoV-2 viral titers in an in vitro human airway epithelium model or the respiratory tract of infected cynomolgus macaques. Formulations containing hydroxychloroquine have been used in the prevention or treatment of malaria, as well as in the treatment of RA and SLE.
Hydroxychloroquine sulfate (also known as hydroxychloroquine) is an antimalarial medicine approved in the United States for either prevention or treatment of certain types of malaria, lupus erythematosus, and rheumatoid arthritis. It is sold under the brand name Plaquenil and it is also sold as a generic medicine. It is available in tablets of 155mg base (200mg salt).
