Plaquenil is used to treat or prevent malaria, a disease caused by parasites that enter the body through the bite of a mosquito. Malaria is common in areas such as Africa, South America, and Southern Asia. Plaquenil for ra Hydroxychloroquine monitoring requirements Hydroxychloroquine side effects clinial studies Lupus and plaquenil problems Tell your doctor if any of the following side effects, as they may be indications of a more serious reaction Headache. Loss of appetite. Dizziness. Nausea. Diarrhea, vomiting, or stomach pain. Skin rash. Hello all, I am currently new to this site and ran across the discussion about stopping Plaquenil. I have been taking Plaquenil for about 8-9 months and thought that it was not helping me because I still have a fair amount of joint pain, fatigue, muscle pain and so many other issues. Nov 09, 2018 Common side effects may include headache, dizziness, ringing in your ears; nausea, vomiting, stomach pain; loss of appetite, weight loss; mood changes, feeling nervous or irritable; skin rash or itching; or. hair loss. Plaquenil is also an antirheumatic medicine and is used to treat symptoms of rheumatoid arthritis and discoid or systemic lupus erythematosus. This medicine is not effective against all strains of malaria. Side effects from taking plaquenil Taking Plaquenil for Rheumatoid Arthritis, Stopping plaquenil. DailyStrength Hydroxychloroquine sulfate arthritisMethotrexate trexall and hydroxychloroquine plaquenilTamiflu and plaquenil RARE side effects. If experienced, these tend to have a Severe expression. Abnormal Liver Function Tests. Acute Liver Failure. Acute Pustular Eruptions On Skin. Bronchospasm. Decreased Blood Platelets. Decreased White Blood Cells. Common and Rare Side Effects for Plaquenil Oral. Hydroxychloroquine - Side Effects, Dosage, Interactions.. Hydroxychloroquine MedlinePlus Drug Information. Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Find patient medical information for Hydroxychloroquine Oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. Get medical help right away if you have any very serious side effects, including sensitivity to light, vision changes e.g. blurred vision, seeing light flashes/streaks/halos, missing/blacked-out areas of vision, muscle weakness, numbness/tingling/pain of the arms/legs.