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. Is plaquenil an anticoagulant Hydroxychloroquine sulfate monitor Plaquenil gut bacteria 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 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. 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. 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 gastrointestinal side effects Hydroxychloroquine Plaquenil Success, Reviews and Side., Hydroxychloroquine - Side Effects, Dosage, Interactions. Plaquenil and celebrex interaction 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. Hydroxychloroquine - Wikipedia. Hydroxychloroquine Plaquenil. Hydroxychloroquine Side Effects, Dosage, Uses, and More. Hydroxychloroquine is a well-tolerated medication for various rheumatologic and dermatologic conditions. Its main side effects are gastrointestinal upset, skin rash, headache, and ocular toxicity1. Within the eye, hydroxychloroquine can adversely impact the cornea, ciliary body, and retina1 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. What are some other side effects of Hydroxychloroquine? All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away Dizziness. Headache. Feeling nervous and excitable.