Plaquenil is used to treat certain auto-immune diseases (lupus, rheumatoid arthritis). It belongs to a class of medications known as disease-modifying anti-rheumatic drugs (DMARDs). It can reduce skin problems and prevent swelling/pain and flares in Lupus, though it is not known exactly how the drug works.
I have to use the name-brand Plaquenil as I seem to be mildly allergic to the generic (rash). But I've been on it since 2002 without any noticeable side effects. Once in a while, it can start to affect your eyesight, and your doctor should have advised you to see an
ophthalmologist at least once a year s a precaution.
There is also an on-line test that you can do at home -
Plaquenil and Your Eyes. This page will also give you more information.
Hope you feel better soon,