https://www.selleckchem.com/products/Estradiol.html ore often mentioned in primary RP and color change in secondary RP. • Over 25% of patients included reduced the quality of life as part of their RP definition. • The concept of "attack" is used to define RP by only 2% of patients. The American Academy of Ophthalmology (2016-AAO) recommended hydroxychloroquine (HCQ) dose not to exceed 5 mg/kg/day (real body weight). Recently, it was reported that prescribed 2016-AAO dose provided adequate HCQ levels for most lupus nephritis (LN) patients, with low flare risk. However, the minimum HCQ dose required to keep adequate levels is unknown. To evaluate if a further reduction in 2016-AAO dose (2-3 mg/kg/day) would sustain 12-month HCQ levels in LN patients with stable inactive disease. Seventy-three stable LN patients under prescribed full HCQ 2016-AAO dose for ≥6 months and adequate baseline HCQ levels (≥613.5 ng/mL) were divided in two groups reduced 2016-AAO dose (2-3 mg/kg/day), n = 32, and full 2016-AAO dose (5 mg/kg/day), n = 41. All patients were assessed at baseline, 3, 6, and 12 months. HCQ levels were measured by liquid chromatography-tandem mass spectrometry. Flare was defined as augment ≥ 3 in SLE Disease Activity Index-2000 and/or change in treatment. Rigorous clinical/laboratlmology (2016-AAO) hydroxychloroquine (HCQ) dose (2-3 mg/kg/day, real body weight) is unable to sustain HCQ blood levels within the safe cut-off defined for flare risk. • Full 2016-AAO dose (5 mg/kg/day) maintains a safe pattern of HCQ levels up to 12 months. ClinicalTrials.gov NCT03122431, registered on April 20, 2017 Key Points • Reduced American Academy of Ophthalmology (2016-AAO) hydroxychloroquine (HCQ) dose (2-3 mg/kg/day, real body weight) is unable to sustain HCQ blood levels within the safe cut-off defined for flare risk. • Full 2016-AAO dose (5 mg/kg/day) maintains a safe pattern of HCQ levels up to 12 months. To test the hypothesis that greater extracellular-to-intracellular wate