This eye toxicity limits long-term use of the drugs. The risk of toxicity is low for individuals without complicating conditions during the first 5 years of treatment using less than 6.5 mg/kg/day of hydroxychloroquine or 3 mg/kg/day of chloroquine, and/or cumulative doses of less than 1000 gram and 460 gram (total dose), respectively. Alternativesto taking plaquenil Plaquenil low cost Chloroquine resistant malaria drugs It is recognized, however, that retinal toxicity is occasionally seen in apparently low-risk individuals, inviting the possibility that there may be genetic or other as yet unrecognized risk factors or alternative causes of retinopathy, as these can be hard to distinguish clinically, especially in early stages. Other risk factors include Obesity. Duration of use cumulative dose. Renal or hepatic functional impairment. Compromised kidney and/or liver function can lead to increased accumulation of hydroxychloroquine in the tissues. Age over 60 years. Preexisting retinal disease. Concurrent tamoxifen. The American Academy of Ophthalmology AAO established guidelines for CQ and HCQ retinopathy screening examinations, which was revised in 20.3,4 Patients were classified as high risk when they have at least one of the following risk factors an average daily dose exceeding 2.3 mg/kg real weight for CQ and 5 mg/kg real weight for HCQ,4 cumulative doses exceeding 460 g for CQ and 1,000 g for HCQ,3 a duration of treatment exceeding 5 years, being elderly, having concomitant renal. The earliest signs of toxicity include bilateral paracentral visual field changes (best detected with a red test object) and a subtle granular depigmentation of the paracentral RPE. Some physicians suggest that lean body weight is more accurate when calculating daily dosage. Hydroxychloroquine retinopathy risk factors Revised Recommendations on Screening for Chloroquine and., Plaquenil Risk Calculators Chloroquine and viral titrePlaquenil pill picture A large study population permitted detailed analysis of risk factors with sub-group analysis such as risk of retinopathy in different ranges of doses by weight. The overall prevalence of HCQ retinopathy was 7.5%, but this increased to around 20% after 20 years of use for those taking 4.0–5.0 mg/kg ABW/day. Hydroxychloroquine retinopathy Eye. Incidence of and risk factors for chloroquine and.. Recommendations on Screening for Chloroquine and Hydroxychloroquine.. Major risk factors for hydroxychloroquine-induced retinopathy include a cumulative dose of more than 1000 g, 3 a daily dose of more than 6.5 mg/kg, 3 duration of treatment longer than five years, 9 development of age-related changes to the eye, 10 pre-existing retinopathy, 7 kidney or liver disease, 4 and concurrent use of tamoxifen. 4 Risk factors for retinopathy normal daily doses range 75-300mg toxicity has been reported with doses of 1200 to 2400 mg/day for 1 to 2 years. Mechanism - Inhibition of retinal enzymes and phototoxicity have been suggested as possible causes of the retinal degeneration. Over 80 % of patients taking 4-aminoquinolines 4AQs have risk factors for retinopathy. The most important risk factor is the adjusted daily dose. Taking hydroxychloroquine at a dose less than 6.5 mg/kg/d based on the lesser of actual and ideal body weight is typically safe.