Because it is effective in treating the symptoms of lupus.
Plaquenil (hydroxychloroquine) is a medication most known for its original purpose of treating or preventing malaria, (a disease caused by parasites that enter the body through the bite of a mosquito). Hydroxychloroquine (trade name Plaquenil) is a disease-modifying anti-rheumatic drug (DMARD). It reduces the activity of the immune system, which can become overactive in diseases like rheumatoid arthritis and lupus, and so affects the underlying disease process rather than simply treating symptoms. Hydroxychloroquine (Plaquenil), chloroquine (Aralen), and quinacrine (Atabrine) are medications that were originally used to prevent or treat malaria. However, during World War II it was also found that these medications were effective in treating the symptoms of lupus. The drug of choice for systemic lupus erythematosus (SLE or Lupus) and rheumatoid arthritis. Hydroxychloroquine is a one of a number of drugs which have been used for many years in the treatment of malaria. Hydroxychloroquine (Plaquenil) is the most commonly prescribed because it is generally believed to cause fewer side effects; chloroquine (Aralen) has a reputation for more serious side effects, but it may be prescribed in situations where hydroxychloroquine cannot be used. Here are the three most common antimalarial drugs prescribed for lupus: 1  Hydroxychloroquine (Plaquenil): This is the most commonly prescribed antimalarial because it is generally believed to cause fewer side effects than the others. ( 2 Learn about side effects further down in this blog). Hydroxychloroquine is in a class of medications that was first used to prevent and treat malaria. Today it is used to treat rheumatoid arthritis, some symptoms of lupus, childhood arthritis (or juvenile idiopathic arthritis) and other autoimmune diseases. Today, Plaquenil and other antimalarials are also used to treat and help prevent symptoms caused by certain autoimmune diseases such as rheumatoid arthritis (RA), systemic lupus erythematosus, and discoid lupus, even though these diseases are not caused by malaria parasites. The two types of antimalarials most often prescribed today for lupus are hydroxychloroquine (Plaquenil®) and chloroquine (Aralen®). Unlike the rapid response seen with steroids, it may take months before antimalarial drugs improve your lupus symptoms.
http://www.mollysfund.org/2015/01/plaquenil/ http://www.arthritisresearchuk.org/arthritis-information/drugs/hydroxychloroquine/what-it-is.aspx http://www.hopkinslupus.org/lupus-treatment/lupus-medications/antimalarial-drugs/ http://www.itzarion.com/plaquenil.html http://www.hopkinslupus.org/lupus-treatment/lupus-medications/antimalarial-drugs/ http://www.mollysfund.org/2015/01/plaquenil/ https://www.rheumatology.org/I-Am-A/Patient-Caregiver/Treatments/Hydroxychloroquine-Plaquenil http://www.mollysfund.org/2015/01/plaquenil/ http://www.lupus.org/answers/entry/medications-to-treat-lupus
why is hydroxychloroquine prescribed for lupus