It would probably save more lives to just legalize all drugs. Until drugs are legalized and quality controlled there will be no way for consumers to even know what they're getting.
Heroine is a prime example. Whilst the argument could be given for "Educated use" you must take into account that the greater population at large will not educate themselves, and will come to harm - mainly through addiction.
Cigarettes are a nice example. We spend vast quantities of money on health care for people who smoke - the information is there, everybody knows that it causes cancer, yet huge amounts of people do it. We would be better off as a planet if everyone just stopped.
Whilst incarceration clearly is not the correct response to addicts, some form of regulation is needed to protect idiots from themselves.
The supply chain funds warlords and criminal gangs. Impurities in the heroin cause abcesses and the need for amputation for injecting users. Restrictions on needles cause spread of blood-borne disease - and this also affect low wage workers who have handle sharps in public bathrooms and so on. People need money to feed their addiction and so they turn to prostitution[1] or acquisitive crime.
Treating heroin as a criminal problem has failed to protect people from themselves, but it also fails to protect wider society.
I do agree that we need to be cautious though. Look at the mess caused by alcohol. (That may be more true in the UK than the US.)
And you only have to look at Russia to see what happens when supply completely dwindles to addicts of hard drugs, the krokodil epidemic is truly horrifying.
My point is just that a free for all on all drugs no matter what harm they cause could be disastrous for society as a whole, as you mention there are plenty of people that currently use alcohol to escape their problems that are in difficult places, especially in poorer demographics. Imagine if they could get hold of heroine or methamphetamines on a whim.
It's a fine balance and I personally cannot see a good way to strike one that will keep everybody safe and happy.
There are plenty of drugs which if used responsibly I could see being legal though, marijuana, ecstasy and some hallucinogens to name a few. If taxed the government could stand to make a lot of money from them as well.
Yes, legalizing will be dangerous; people will still do heroin, become addicted, and possibly die. But the harm of such use is shifted from a wider group, to a much smaller group largely consisting of users who have made the decision for themselves.
But drugs like Ice, Meth or Heroin are incredibly dangerous, toxic and addictive regardless of how well they are made. Making them readily accessible to existing addicts makes sense. But to first-time users ? No way.
Most heroin ODs are actually the reverse problem....a frequent user gets something that for once ISN'T cut, takes their normal dose and instantly ODs. Even that is easily handled if Narcan is available.
I'm not saying anyone should use heroin, but from a purely pharmaceutical standpoint it isn't an especially dangerous drug, and in many places (but not the US) is used for the treatment of severe pain. Something like Oxycontin is harder on the body due to the acetaminophen.
Anyway, you can legalize all these drugs, but make the harder ones prescription only and highly taxed.
According to Wikipedia, it's 120,000 alone in Mexico's recent drug war. Colombia has been one of the most violent places on earth for decades now. And it's not a coincidence that we're dealing with terrorism threats from the country that produces 70% of the world's opium. The number of people who've had their lives ruined by illegal drugs goes way beyond those that consume those drugs.
In this program they explored something not so obvious about legalizing drugs, namely that the pharmaceutical industrial complex would fill the market with many new drugs, think the current issues with legal highs but industrial scale. Another point is drug interactions are very unpredictable and very difficult to test.
This show is probably available on the web somewhere, here's the bbc page about it: http://news.bbc.co.uk/2/hi/programmes/if/4075235.stm
Imagine if we unleashed the full power of science and capitalism at the problem!
Of course we would need to find a regulatory framework that allowed us to optimise for that outcome rather than for addiction...