Hydroxychloroquine

Hydroxychloroquine is used to treat autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis, in addition to malaria.
Hydroxychloroquine is a disease-modifying anti-rheumatic drug (DMARD). It regulates the activity of the immune system, which may be overactive in some conditions. Hydroxychloroquine can modify the underlying disease process, rather than simply treating the symptoms.
Hydroxychloroquine is used to treat:
rheumatoid arthritis
discoid and systemic lupus erythematosus (SLE)
juvenile idiopathic arthritis (JIA).
Over the long term hydroxychloroquine can reduce pain, swelling and joint stiffness. If you have lupus, it may also improve the rash. It may be as long as 12 weeks before you notice the benefits.

ChEBI: 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 s the sulfate salt for the treatment of lupus erythematosus, rheumatoid arthritis, and light-sensitive skin eruptions.

Hydroxychloroquine (Plaquenil), like chloroquine, is a 4-aminoquinoline derivative used for the suppressive and acute treatment of malaria. It also has been used for rheumatoid arthritis and discoid and systemic lupus erythematosus. Hydroxychloroquine has not been proved to be more effective than chloroquine. Adverse reactions associated with its use are similar to those described for chloroquine.The drug should not be used in patients with psoriasis or porphyria, since it may exacerbate these conditions.

Hydroxychloroquine, like chloroquine, is also used for treating acute forms of malaria caused by P. vivax, P. malariae, P. ovale, and also sensitive forms of P. falciparum. It is also effective and safe like chloroquine, although it does not have obvious advantages. The only advantage is that it is somewhat better tolerated. Its use is somewhat more limited than chloroquine. Synonyms of this drug are plaquenil, quensyl, toremonil, and others.

Hydroxychloroquine is approved for the treatment of both systemic and cutaneous lupus erythematosus. Both chloroquine and quinacrine (Atabrine) are also effective in this skin disease. Low-dose chloroquine is used for the therapy of porphyria cutanea tarda in patients in whom phlebotomy has failed or is contraindicated. Other skin diseases in which the drugs are useful (after sunscreens and avoidance of sun exposure) include polymorphous light eruption and solar urticaria.