Although not all of these side effects may occur, if they do occur they may need medical attention. Check with your doctor immediately if any of the following side effects occur while taking hydroxychloroquine: Incidence not known Some side effects of hydroxychloroquine may occur that usually do not need medical attention. Hydroxychloroquine shelf life Hydroxychloroquine sulfate advers reactions Find user ratings and reviews for Plaquenil oral on WebMD including side effects and drug interactions, medication effectiveness, ease of use and satisfaction Hydroxychloroquine Plaquenil is a drug that is classified as an anti-malarial drug. Plaquenil is prescribed for the treatment or prevention of malaria. It is also prescribed for the treatment of rheumatoid arthritis, lupus, and the side effects of lupus such as hair loss, joint pain, and more. Plaquenil is prescribed for the treatment or prevention of malaria. It is also prescribed for the treatment of rheumatoid arthritis, lupus, and the side effects of lupus such as hair loss, joint pain, and more. Side effects, drug interactions, pregnancy safety information, and dosage information should be reviewed prior to taking this medication. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. These side effects may go away during treatment as your body adjusts to the medicine. Information on the medication plaquenil Plaquenil hydroxychloroquine sulfate Drug / Medicine., Hydroxychloroquine Plaquenil Side Effects & Dosage for Malaria Plaquenil 200 mg reviews Plaquenil is the brand name for the prescription drug hydroxychloroquine. It's used to treat and prevent malaria infection, and to reduce symptoms and progression of autoimmune diseases such as. Plaquenil Hydroxychloroquine - Side Effects, Dosage.. Hydroxychloroquine Plaquenil Side Effects & Dosage for.. Plaquenil Hydroxychloroquine Uses, Dosage, Side Effects.. Dosage for Plaquenil. The adult dose of Plaquenil to suppress malaria is 400 mg on the same day each week. The pediatric weekly suppressive dosage is 5 mg/kg of body weight. The adult dose of Plaquenil to treat an acute attack of malaria is an initial dose of 800 mg followed by 400 mg in six to eight hours and 400 mg for two more days. Hydroxychloroquine is also an antirheumatic medicine and is used to treat symptoms of rheumatoid arthritis and discoid or systemic lupus erythematosus. Important information. Taking hydroxychloroquine long-term or at high doses may cause irreversible damage to the retina of your eye. A drug developed over half a century ago to treat malaria is showing signs that it may also help cure COVID-19 -- especially when combined with an antibiotic, a promising new study reveals.