Multifaceted effects of hydroxychloroquine in human disease.

Objectives: Hydroxychloroquine (HCQ) is a widely used medication for the treatment of rheumatoid arthritis and systemic lupus erythematosus. An increasing body of evidence supports actions of this drug that are not directly related to its immunosuppressive or anti-rheumatic properties. The objective of this systematic review is to characterize the spectrum of conditions that might be responsive to treatment with HCQ.