Hydroxychloroquine is available as the brand-name drug Plaquenil. Generic drugs usually cost less than the brand-name version. Hydroxychloroquine may be used as part of a combination therapy. Malarone versus chloroquine Chloroquine related chloroform Benadryl and hydroxychloroquine 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. Side Effects. Nausea, stomach cramps, loss of appetite, diarrhea, dizziness, or headache may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly. 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. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about. Hydroxychloroquine is used to treat lupus erythematosus and rheumatoid arthritis. It isn’t fully understood how this drug works to treat lupus erythematosus or rheumatoid arthritis. That means you may need to take it with other drugs. It treats malaria by killing the parasites that cause the disease. Effects of plaquenil Taking Plaquenil for Rheumatoid Arthritis, Plaquenil Oral Uses, Side Effects, Interactions. Chloroquine in hepatic dysfunctionChloroquine sle doseHydroxychloroquine at night SIDE EFFECTS. The following adverse reactions have been identified during post-approval use of PLAQUENIL or other 4-aminoqunoline compounds. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Side Effects of Plaquenil Hydroxychloroquine, Warnings, Uses. Hydroxychloroquine Oral Route Side Effects - Mayo Clinic. Plaquenil Hydroxychloroquine Uses, Dosage, Side Effects.. Common Plaquenil side effects - a study from FDA data Summary In this review, we analyze Plaquenil side effects by the time on the drug, gender and age of the people who have side effects while taking Plaquenil. Long-Term Side Effects of Plaquenil for Rheumatoid Arthritis Retinal Damage. Neurological Disorders. Blood Disorders. Hearing Disorders. Other Side Effects. Plaquenil is the brand name of hydroxychloroquine, a drug used to prevent or treat malaria. Plaquenil can cause serious side effects when used in high doses for chronic diseases such as RA over the long term.