Minor Hydroxychloroquine Toxicity on a non-toxic dose

Legend: This 38-year-old woman had been taking hydroxychloroquine at a dose of 400 mg/d for 21 years for systemic lupus erythematosus. She had no visual complaints and was seen for routine retinopathy screening evaluations. Her height was 66 inches and her weight 210 pounds. She had no liver or renal disease. D: Multifocal electroretinography was normal bilaterally based on normal amplitudes in all rings and a normal R1/R2 ratio. E: Spectral domain optical coherence tomography showed slight decreased reflectivity of the pericentral retinal pigment epithelial layer (yellow arrows) bilaterally. Although her daily dosage of hydroxychloroquine was 5.94 mg/kg based on an ideal body weight of 148 pounds, a typically nontoxic dosage, it was recommended that she decrease her hydroxychloroquine daily dosage to 300 mg. She had no relapse in lupus activity. She was asked to return for a recheck in six months rather than one year.