ACCELERATED ONSET OF RETINAL TOXICITY FROM HYDROXYCHLOROQUINE USE WITH CONCOMITANT BREAST CANCER THERAPY.

PURPOSE: To report a case of accelerated retinal toxicity due to hydroxychloroquine (HCQ) use for treatment of Sjogren syndrome in a patient treated with concomitant chemotherapy for breast cancer. METHODS: Observational case report. RESULTS: A 56-year-old white woman using 400 mg HCQ (7.1 mg/kg real body weight) daily for a total of 2 years and 10 months for treatment of Sjogren syndrome with concomitant use of docetaxel and cyclophosphamide therapy (21-day cycle, 4 cycles) followed by anastrozole for breast cancer, presented with visual complaints and findings of severe HCQ toxicity. CONCLUSION: Concomitant breast cancer therapy may have a synergistic effect with HCQ leading to accelerated retinal toxicity. As such potential acceleration is poorly understood, patients on HCQ who are treated with concomitant chemotherapy should be considered for more frequent retinal screenings to maximize safety and preservation of vision.