Considerations before hydroxychloroquine use

Measure glucose-6 phosphate dehydrogenase if indicated
Take ocular history and order baseline ophthalmologic evaluation
Screen for digoxin use
Screen for history of cardiomyopathy or severe heart failure
Counsel patient on risks of use, including permanent loss of vision and recommended frequency of screening retinal examination
Counsel on risks of skin rashes, gastrointestinal upset, increased hair and skin pigmentation
Obtain baseline laboratory testing