[MichaelGG]

No, my point is that "hard drugs" like heroin are vastly more dangerous because users cannot use properly whilst the drug remains illegal. It's a manufacturing and usage problem. Opiates are rather tame as far as side effects go, and avoiding overdoses isn't terrifically hard if you have the right stuff. Users don't want to waste precious medicine, nor die. With precision markings, there'd be vastly less problems reaching the right level of usage. Instead, users are admonished to "do a test shot" each time, which, through laziness or practical concerns, gets ignored and someone falls out.

But let me understand you: Are you saying that if someone is in pain, their respiratory system just ignores opiates and they can take large doses even if they're opiate naive? Does this work retroactively, like if you don't have Narcan handy can you just snap someone's leg to save them? (And then, with a broken bone, they'd certainly get medicated - double win!)

Sarcasm aside, do you have a citation for this claim? That opiate tolerance doesn't matter in face of pain? That there's a "fundamental difference" in the effect? I'm truly interested in hearing about that (feel free to contact me via my profile if this thread is too long).

Everything I've read and experienced says otherwise. I've talked with some users that were taking opiates for cancer pain management, or for otherwise long-term pain, and they just as happy to take them as unlicensed users (though perhaps a bit more cautious in admitting so). In personal experience from acute trauma leading to a hospital team applying morphine, I went from screaming in pain to absolute noddy-head bliss. I'm pretty sure that's the exact effect people are seeking.

[Gatsky]

I agree they are vastly more dangerous because they are illegal. But you know, alcohol is legal, and people still binge drink, fall in ditches, have random unprotected sex, get pancreatitis etc... and it isn't even addictive. I'm just trying to say that even if heroin were legal, it would still be unacceptably dangerous, because at the end of the day it's a highly addictive general anaesthetic. Even with 'vastly less' problems, which is your conjecture, there are still significant problems. Anyway, we both clearly think that harm minimisation is a good policy.

Yes, that's right, if someone is in pain, the respiratory depression is less. This is evident to anyone that prescribes opioids regularly or looks after people with chronic and acute pain (as I do). It is also evident that the ever escalating doses and withdrawal symptoms demonstrated by recreational users of heroin for example, are not manifested in people with pain. So that's why I use the word 'fundamental difference', because the coupling between dosage, physiological response and behavior is completely different.

Lots of people don't enjoy taking opioids, they get nausea, nightmares, constipation etc, or it just doesn't work for their pain. I know this because that is what is reported in controlled trials, and because people complain to me about these side effects all the time.

Reference: http://www.ncbi.nlm.nih.gov/pubmed/8867254

More general overview: http://bja.oxfordjournals.org/content/100/6/747.full

(Glad you are truly interested, but in the time it took to write your sarcastic comment, you could have just googled it, and we'd both be better off right now.)