It is possible you have P450 problems in the way your process drugs. Just be on the lookout for other weird reactions to drugs.
For me, I am completely missing the enzymes from both parents that would metabolize that drug. But you can have a problem even if only one parent gave you the enzyme.
Also some pain drugs are metabolized by multiple enzymes. So if you are okay with one set but are defective in another it might still cause you problems.
That is what I have to watch out for with Plaquenil.
And then there is the whole other nightmare of how one drug effects another when you have P450 problems
Acetaminophen and Codeine work great!