Chloroquine phosphate, which has been used for more than 70 years and is on the World Health Organization’s List of Essential Medicines, the safest and most effective medicines needed in a health system. Chloroquine was discovered in 1934 by Hans Andersag but was initially ignored for a decade because it was considered too toxic for human use. Plaquenil and radiation Ocular testing for plaquenil Plaquenil sore throat Hydroxychloroquine has also been used as an antimalarial, but in addition is now broadly used in autoimmune diseases such as lupus and rheumatoid arthritis. Of note, chloroquine and hydroxychloroquine are considered to be safe and side-effects are generally mild and transitory. Contraindications Hypersensitivity to hydroxychloroquine, chloroquine, or 4-aminoquinolines Precautions Use caution in hepatic disease, psoriasis, and porphyria. Reports suggest that antimalarials may exacerbate psoriasis, but they were often safely used to treat psoriatic arthritis. Rheumatoid Arthritis. PLAQUENIL is indicated for the treatment of acute and chronic rheumatoid arthritis in adults. CONTRAINDICATIONS. Use of PLAQUENIL is contraindicated in patients with known hypersensitivity to 4 aminoquinoline compounds. WARNINGS. Resistant strains of malaria PLAQUENIL is not effective against chloroquine-resistant. Aside from preventing and treating malaria, chloroquine is also occasionally used for amebiasis that is occurring outside the intestines, rheumatoid arthritis, and lupus erythematosus. During World War II, United States government-sponsored clinical trials for antimalarial drug development showed unequivocally that chloroquine has a significant therapeutic value as an antimalarial drug. Chloroquine phosphate rheumatoid arthritis Chloroquine Phosphate - WebMD, Hydroxychloroquine and Chloroquine Phosphate - RheumaKnowledgy What are some side effects of hydroxychloroquine The 4-aminoquinoline derivatives, including chloroquine, also have anti-inflammatory activity; however, the mechanisms of action of the drugs in the treatment of rheumatoid arthritis and lupus erythematosus has not been determined. Chloroquine reportedly antagonizes histamine in vitro, has antiserotonin effects. Chloroquine phosphate C18H32ClN3O8P2 - PubChem. PLAQUENIL HYDROXYCHLOROQUINE SULFATE TABLETS, USP DESCRIPTION. Chloroquine Side Effects Common, Severe, Long Term -. Response may not occur until after 4–6 weeks of therapy. a Some clinicians recommend the drug be continued for 4 months before being considered ineffective for treatment of rheumatoid arthritis. a. Lupus Erythematosus† Oral. 150 mg 250 mg of chloroquine phosphate daily. a Disease Modifying Anti-rheumatic Drugs DMARDS Methotrexate Rheumatrex®, Trexall® Hydroxychloroquine Plaquenil ® Sulfasalazine Azulfidine® Leflunomide Arava® Tumor Necrosis Factor Inhibitors — etanercept Enbrel®, adalimumab Humira ®, and infliximab Remicade®, certolizumab pegol Cimzia. Despite widespread clinical use of antimalarial drugs such as hydroxychloroquine and chloroquine in the treatment of rheumatoid arthritis RA, systemic lupus erythematosus SLE and other.