Hydroxychloroquine is also used in the treatment of lupus and rheumatoid arthritis.

Antimalarial drugs were used to treat lupus as early as 1834. The FDA approved hydroxychloroquine as a treatment for both systemic lupus and rheumatoid arthritis in 1956.

It was shown to be effective in reducing the number of disease flares, reducing long-term damage, and delaying ultraviolet light absorption in lupus patients (photosensitivity is common among people with lupus).

In the case of rheumatoid arthritis, hydroxychloroquine can reduce pain and swelling, protect joints, and lower the risk of long-term disability.