Continuation Rate, Safety and Efficacy of Hydroxychloroquine Treatment in a Retrospective Cohort of Systemic Lupus Erythematosus in a Japanese Municipal Hospital

OBJECTIVE: We investigated the continuation rate, safety and efficacy of treatment with hydroxychloroquine (HCQ) in a retrospective cohort of systemic lupus erythematosus (SLE) in a Japanese municipal hospital. METHODS: All of the patients with SLE who started treatment with HCQ were included in this study. A retrospective chart review was performed. Our primary outcomes were the continuation rate of HCQ treatment for 1 year and adverse events (AEs) during the treatment. We also investigated the efficacy of HCQ treatment in cases in which treatment with immunosuppressive therapies remained unchanged for the preceding six months. RESULTS: Forty-seven patients with SLE were included in this study. Twenty-five patients (53.2%) had AEs. Eleven (64.7%) of the 17 patients who tried the readministration of HCQ could continue HCQ treatment. The continuation rate of HCQ for a period of 1 year was 78.3% (36 of 46 patients). The development of cutaneous lesions was the most frequent adverse event (25.5%) followed by gastrointestinal symptoms (8.5%). In the 16 cases in which the immunosuppressive therapies remained unchanged for at least six months prior to starting HCQ treatment, the SLE disease activity index, anti-DNA antibody, immune complex, and serum complement activity significantly decreased over a period of 1 year, while the prednisolone dose significantly decreased. CONCLUSION: The continuation rate of HCQ treatment was high in an SLE cohort of a Japanese municipal hospital. Although more than half of the patients experienced AEs, the readministration of HCQ was often successful. HCQ treatment provided benefits regarding the clinical and immunological findings in Japanese patients with SLE, which would likely lead to glucocorticoid tapering.