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 chloroquine: Incidence not known Some side effects of chloroquine may occur that usually do not need medical attention. Big blood clots during period with plaquenil Plaquenil side effects constipation The actual incidence of retinal toxicity from hydroxychloroquine is difficult to pin down because there is usually a long time between being started on the drug and the start of any identifiable retinal toxicity. The overall rate of probable retinal toxicity is in the range of 1 of every 200 people treated. To reduce the incidence of chloroquine and hydroxychloroquine toxicity, health care providers HCP's that prescribe these medications and those that screen for ocular toxicity have developed clear dosing and screening protocols that have reduced the risk of end-stage disease; bull's eye maculopathy and central vision loss Level I. More in Eye Health. If you are taking Plaquenil to treat an inflammatory condition or malaria, you should be aware of the side effects that may occur to your eyes and vision. Plaquenil hydroxychloroquine is in a class of drugs called disease-modifying anti-rheumatic drugs, which are used to decrease inflammation, pain and joint 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. Chloroquine eye toxicity Hydroxychloroquine And Chloroquine Screening 2016 AAO., Chloroquine And Hydroxychloroquine Toxicity - StatPearls. How much is plaquenil without insuranceHow long does it take for chloroquine to workDoes hydroxychloroquine affect bone graft healingChloroquine sle mechanism The usefulness of hypokalemia as an indicator in the evaluation of chloroquine toxicity was studied in a retrospective series of 191 acute chloroquine poisonings. Results indicated that the risk of severe poisoning and death are proportional to the degree of hypokalemia. Chloroquine Side Effects Common, Severe, Long Term.. Plaquenil Side Effects on Your Eyes and Vision. Has anyone experienced plaquenil toxicity with damage to eyes?. In view of the fact that all electron micro scopic studies on chloroquine toxicity in the eye have to date been limited to experimental animals, and because our experience has shown that tissues routinely fixed in Forma lin may occasionally be helpful in such stud ies,2 we decided to re-examine the material available from Wetterhold and Winter. Color photograph of left eye documenting end-stage chloroquine retinal toxicity, with disc pallor, vascular attenuation, diffuse pigment mottling, and pigment deposition along the peripheral retinal vessels similar to retinitis pigmentosa. Visual acuity was 20/200. Retinal toxicity from chloroquine CQ and its analogue, hydroxychloroquine HCQ, has been recognized for many years. Chloroquine toxicity remains a problem in many parts of the world, but is seen less frequently in the United States where the drug largely has been replaced by HCQ.