I'd say tax it the way Scands, Aussies and Kiwis do (perhaps even more, plus put each use on your medical record (in NZ you are already bumped down in wait list if you are alcoholic + need a liver transplant).

Additionally, for opioid, I think it should be possible to create tamper-proof cartridges that only release when get correct key signature from master device that tracks your usage (and identity via smartphone). Many opioid users claim drug is safe minus overdoses and purity issues that care caused by it's illegal status.

The problem of all of this - it's trivial to grow marijuana or produce alcohol (or order fentanyl from China via darknet). It's already cheaper to get stoned in NZ than drink (or smoke cigarettes). Not sure we should be put up a fight here after all. If we can't decrease use via economics, then at least there should be accountability for your abuse (not an issue for countries like US with no socialised health care).