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 infection Do i need to take folic acid with plaquenil Chloroquine resistance testing Basic description of chloroquine Plaquenil hydroxychloroquine is an antimalarial medication used to treat or prevent malaria, a disease caused by parasites, which enter the body through the bite of a mosquito. Plaquenil is also used to treat symptoms of rheumatoid arthritis and discoid or systemic lupus erythematosus. Chloroquine and hydroxychloroquine can cause toxic retinopathy due to their binding of melanin in the retinal pigmented epithelium RPE as well as direct toxicity to retinal ganglion cells. Early findings include mottling of the RPE and blunted foveal reflex. Hydroxychloroquine is an effective and relatively safe drug that can cause retinal toxicity in a minority of patients. Early diagnosis is important to stop treatment and prevent possible further damage. 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. Hydroxychloroquine toxicity Hydroxychloroquine - Wikipedia, Bull's-eye maculopathy due to hydroxychloroquine toxicity Plaquenil 6mg kgPlaquenil peakLife extension chloroquinePlaquenil bleeding Factors associated with hydroxychloroquine toxicity include the following Maintenance dose greater than 5 mg/kg/d based on real weight most critical risk Daily dose greater than 400 mg Chloroquine and Hydroxychloroquine Toxicity Practice Essentials.. Retinal Physician - Hydroxychloroquine Maculopathy An.. Hydroxychloroquine Oral Route Side Effects - Mayo Clinic. Note This document contains side effect information about hydroxychloroquine. Some of the dosage forms listed on this page may not apply to the brand name Plaquenil. For the Consumer. Applies to hydroxychloroquine oral tablet. Along with its needed effects, hydroxychloroquine the active ingredient contained in Plaquenil may cause some. The Risk of Retinal Toxicity with Plaquenil. Plaquenil, hydroxychloroquine HCQ, is an anti-malarial medication that has been proven to be useful in the treatment of patients with rheumatoid arthritis RA, systemic lupus erythematosus SLE and other inflammatory and autoimmune diseases. Hydroxychloroquine can cause serious vision problems. If you experience any changes in vision, stop taking hydroxychloroquine and call your doctor immediately.