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. Plaquenil rash sun Difficulty sleeping side effect of plaquenil 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, and Southern Asia. This medicine is not effective against all strains of malaria. 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. Availability. 200 mg tablets. Actions. Derivative closely related to chloroquine. Antimalarial activity is believed to be based on ability to form complexes with DNA of parasite, thereby inhibiting replication and transcription to RNA and DNA synthesis of the parasite. 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. Hydroxychloroquin sulphate Plaquenil Hydroxychloroquine Uses, Dosage, Side Effects., Hydroxychloroquine Uses, Dosage & Side Effects - Plaquenil and tb testChloroquine base 150 mgWhy is chloroquine used to treat lupus Get emergency medical help if you have signs of an allergic reaction hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Taking hydroxychloroquine long-term or at high doses may cause irreversible damage to the retina. Plaquenil, Plaquenil Sulfate, Quineprox hydroxychloroquine.. HYDROXYCHLOROQUINE SULFATE. Hydroxychloroquine Tablets - FDA prescribing information.. Hydroxychloroquine and chloroquine are medications traditionally prescribed to prevent or treat malaria infections. In certain countries and parts of the world where malaria is still present, a person can easily catch malaria from a seemingly insignificant mosquito bite. Hydroxychloroquine sulfate. An antimalarial, antirheumatic drug, often used as a disease-modifying agent in rheumatoid arthritis, systemic lupus erythematosus, and some dermatological diseases. Annual screening is recommended in all patients who have taken hydroxychloroquine for greater than 5 years; Annual screening may be commenced before 5 years of treatment if additional risk factors for retinal toxicity exist, such as concomitant tamoxifen therapy, impaired renal function eGFR less than 60 mL/minute/1.73 m 2 or high-dose therapy greater than 5 mg/kg/day of hydroxychloroquine sulfate.