I really could have used that in geometry in high school...
But seriously, If you don't care about the consequences to the addict, then allow them to off themselves, as they do daily, via overdose. We pay through the nose in increased taxes and social services, foisted on us by the do-gooders, trying to "save" these people from themselves.
Well, that's certainly cold-hearted, but I can't argue with that. But so long as suicide-happy junkies can still vote, they pose a threat, albeit a less obvious one. I guess they usually don't make it to the polls, though.