What can substitute plaquenil (hydroxychloroquine)?

Nothing safer: Plaquenil is also known as hydroxychloroquine, so the parent drug Chloroquine can be substituted. But Chloroquine has significantly higher rate of retinal toxicity, so it isn't used much anymore. Also, Plaquenil appears to effectively reduce flares in patients with lupus not necessarily by suppressing immunity. So other meds like Imuran and CellCept (mycophenolate mofetil) also reduce flares, but also increases infection.