No, they would have made the CHOICE to poison themselves. Drug use is a BEHAVIOR, not a disease. Choose badly and there are consequences.
One would hope, though, that those (and most) individuals would be smart enough to leave the crap alone after the first wave of seriously ill druggies.
Oh, so you want to add a seriously-ill-making component to a drug that can all by itself kill its users? And you think this will substantially increase deterrence? Weird.