The exact wording is if you are an

“unlawful user of or addicted to any controlled substance”.

So a legal prescription to opioids shouldn’t be a disqualifier, unless you become “addicted” which could maybe be up to some interpretation, but if you stick to what your prescribed it would be pretty hard for anyone to prove an addiction

Weed is in a weird place, and I’m not 100% up on the latest stuff with that and how rescheduling will change things, but since it’s still schedule I, as far as the feds are concerned there is basically no legal use for marijuana so pretty much any use is a disqualifier. I don’t know how rigorously they check that against people who have medical cards.