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. Chloroquine lysosomal degradation Hydroxychloroquine plaquenil 200 mg tablet Before taking hydroxychloroquine, tell your doctor and pharmacist if you are allergic to hydroxychloroquine, chloroquine Aralen, primaquine, or any other drugs. tell your doctor and pharmacist what prescription and nonprescription drugs you are taking, especially acetaminophen Tylenol, others, digoxin Lanoxin. Plaquenil Side Effects by Likelihood and Severity. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be. Common Plaquenil side effects may include headache, dizziness, ringing in your ears; nausea, vomiting, stomach pain; loss of appetite, weight loss; mood changes, feeling nervous or irritable; skin rash or itching; or. hair loss. 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. Plaquenil medication side effects Hydroxychloroquine Oral Uses, Side Effects, Interactions., Common and Rare Side Effects for Plaquenil Oral Raking tylenol after using plaquenil Find user ratings and reviews for Plaquenil oral on WebMD including side effects and drug interactions, medication effectiveness, ease of use and satisfaction Plaquenil oral Reviews and User Ratings Effectiveness, Ease of Use.. Plaquenil Uses, Dosage & Side Effects -. Plaquenil, Plaquenil Sulfate, Quineprox hydroxychloroquine Uses, Side.. What Are Side Effects of Plaquenil? nausea, vomiting, stomach pain or cramps, loss of appetite, weight loss, diarrhea, dizziness, spinning sensation, headache, ringing in your ears, 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. 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. Rarely, hydroxychloroquine can lead to anemia in some individuals.