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. Hydroxychloroquine retinopathy screening Using chloroquine to treat glioblastoma Tell your doctor if you have any side effect that bothers you or does not go away. These are not all the possible side effects Plaquenil. For more information, ask your doctor or pharmacist. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. Plaquenil side effects. Get emergency medical help if you have signs of an allergic reaction to Plaquenil hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Taking Plaquenil long-term or at high doses may cause irreversible damage to the retina of your eye. Hydroxychloroquine typically is very well tolerated. Serious side effects are rare. The most common side effects are nausea and diarrhea, which often improve with time. Less common side effects include rash, changes in skin pigment such as darkening or dark spots, hair changes, and muscle weakness. 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. What are the most common side effects of plaquenil Plaquenil Oral Uses, Side Effects, Interactions, Pictures, Warnings., Plaquenil Uses, Dosage & Side Effects - Plaquenil eye exam standard of careWhat is chloroquine Along with its needed effects, hydroxychloroquine the active ingredient contained in Plaquenil may cause some unwanted effects. 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 Plaquenil Side Effects Common, Severe, Long Term -. Hydroxychloroquine Plaquenil. The Risk of Retinal Toxicity with Plaquenil. Plaquenil is generally well-tolerated, but side effects are possible. Common side effects linked to Plaquenil include nausea and diarrhea. Taking the medication with food eases nausea for most people taking the drug. Less common side effects include skin rashes, hair thinning, and weakness. Most do fine. Most patients do very well on hydroxychloroquine. Common side effects include allergy to the medication, GI disturbances such as nausea or diarrhea, and changes of pigmentation in the skin or hair this is not a complete listshould also be tested for an enzyme called g6pd before starting, and you should have at least one eye exam annually while on the drug. Hydroxychloroquine Plaquenil is used to treat malaria, lupus, and rheumatoid arthritis. Learn about side effects, warnings, dosage, and more.