Most unbiased students of drug policy would agree that cannabis should not be prohibited or made illegal. The evidence seems to indicate that making this drug illegal actually increases harm, rather than reduce it. What is a sensible drug policy for Diacetylmorphine or Heroin though?
Heroin has run into stigma, misunderstanding and trouble ever since it was invented in the late 19th century. Over the last 100 years we have learned a great deal about this drug and our societies seem unsure of how to effectively control it and reduce the harms caused by it. The usual response from conservatives and liberals and governments is to introduce a blanket prohibition on the substance. A century ago Heroin moved from legal, to presciption to illegal in virtually all the world, becoming globally illegal with international drug conventions in the 60's and 70's. Needless to say prohibition does not work in practice.
In the 21st century a few nations have been trying some new methods of regulating Heroin and the results are interesting.
I will break the problem down into two, more manageable issues. Firstly is the question of whether Heroin should be used as a prescition analgesic or a pain releiver (which I will address in part one). The second is what to do with people who are addicted too or dependant on illegal Heroin (which will be addressed in part 2).
Heroin as a pain releiver.
Why is Heroin such an effective pain releiver? It is almost entirely due to it's chemical structure and mechanism of action in the brain. Heroin is literally a morphine molecule with two acetyl molecules attached to it. Heroin is also a 'pro-drug', meaning it is metabolized into morphine and monoactylmorphine before it is psychoactive - basically heroin works and feels similiar to morphine because it is morphine.
Then why does heroin produce a more effective pain releif than morphine? The answer is largely due to Heroin's ability to cross the blood brain barrier. Remember those acetyl molecules; well, they make the morphine molecule substantially more fat soluable. This is important pharmacologically as the brain is seperated from the bloodstram by the blood brain barrier. The blood brain barrier is a kind-of fatty membrane, protecting the brain from harm while allowing oxygen, glucose along with other essential compounds into the brain, this membrane also has the characteristic of allowing lipid soluable drugs to pass. Morphine has a very difficult time crossing this barrier and therefore is not as effective at stimulating the brains endorphins. Stimulation of the brains endorphins in turn produces much of the analgesic and relaxing effects of the drug. Heroin on the other hand is much more efficient at crossing the blood brain barrier thereby entering the brain. Think of Heroin as a really good way of getting morphine into the brains neuro-chemical network.
What is the current status of Heroin as a pain releiver? In most of the world it is illegal to use for any reason, including medical reasons. This implies that you or a loved one could be diagnosed with a terminal, unbearably painful illness and you are not allowed to use, arguably, the worlds most effective pain releiver. This seems a failure of compassion if it is anything. It is also a failure of logic and a gross misunderstanding of the drug's effects. For instance, one main risk associated with using Heroin as a presciption medication is addiction to the drug. This is a negligible risk if the person is terminally ill, or in chronic pain because it is likely they are already being presibed a less effective opiate analgesic for the pain, which carries the risk of addiction anyway. Also if they are going to die soon it is borderline psychotic not to allow them effetive pain releif.
What about treatment for non-terminal illness, won't this cause serious problems? That depends on what you mean by serious. Morphine is a remarkably non-toxic drug, like cannabis is - It is less toxic than alcohol for example. Morphine or Heroin can be used for years, even decades and the user is not at risk of the drug causing cancers, serious brain damage or permanent disability. The main risks and harms from prescription heroin are indirect, which means they can be avoided or reduced with education and treatment, or are caused by addiction to the drug - which can be minimized if the drug is taken regularly and at a steady dosage. One issue that cannot be avoided is dependancy to Heroin. Heroin like all opiates causes withdrawal symptoms if it is not taken regularly and at a constant dose. Most of the harms caused by Heroin today are actually caused by the illegailty of the drug. Cheap prescription Heroin could in principle circumvent most of the criminal, overdose, viral, social, economic, and health issues caused by expensive, impure illegal Heroin.
Where is Heroin legal for medical reasons and why is it still illegal? The UK and several European countries use Heroin as a prescription medication for illness, usually as a replacement for morphine or less effective pain releivers. The main hurdles to prescrition Heroin for pain are public stigma and a general misunderstanding of the empirical evidence (for example people attach human attributes to Heroin, describing a molecule as evil - a non-sentence to me, or think it is dangerous necessarily, again an unfounded statement not driven by the facts). Also the US schedules the drug in the most resticted category (Schdule 1), this coupled with the observation that other nations "copy" the US in drug policy and the "war on drugs" means it will be some time before evidence and reason win out.