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. Risks of plaquenil How long does hydroxychloroquine take to work Chloroquine and zambia Plaquenil and hearing loss Hydroxychloroquine is a quinoline medicine 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. This medicine is not effective against all strains of malaria. 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. Find patient medical information for Plaquenil Oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. 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. Side effects of hydroxychloroquine on eye Hydroxychloroquine MedlinePlus Drug Information, Hydroxychloroquine Plaquenil Side Effects & Dosage for Malaria Hydroxychloroquine precautionsWhat time of day to take plaquenil Hydroxychloroquine is a disease-modifying anti-rheumatic drug DMARD used for rheumatoid arthritis and lupus. Learn how long it takes, risks and side-effects. Hydroxychloroquine Side-effects, uses, time to work. Plaquenil Oral Uses, Side Effects, Interactions, Pictures, Warnings.. Hydroxychloroquine Side Effects -. One of the most serious side effects is a toxicity in the eye generally with chronic use. People taking 400 mg of hydroxychloroquine or less per day generally have a negligible risk of macular toxicity, whereas the risk begins to go up when a person takes the medication over 5 years or has a cumulative dose of more than 1000 grams. While side effects of corticosteroids are usually to blame, there is also the possibility of ocular damage associated with long-term use of the antimalarial drugs hydroxychloroquine brand name Plaquenil® and chloroquine. Improved vision screening tests and updated dosing guidelines are key to avoiding such complications. Other drugs in the treatment for RA or Lupus may have more frequent or serious side effects then Hydroxychloroquine so it would be wise to consider it a viable treatment option and not easily dismiss it because of the risk of what amounts to a fairly infrequent eye issue.