I think that Krummhorn has pretty much summed up the importance of prescription drugs – I would only develop what has been said by adding that it is tragic that money comes before health in this world and that developing world nations opften cannot afford the drugs that would help their people, because pharmaceutical corporations must keep their shareholders happy with ever-increasing profits. This to the extent that companies threaten countries that create 'copies' of such drugs. The same can also be said of countries that do not have a proper healthcare system, where people who are sick cannot afford to get care – or drugs, if required – because they cannot afford the kind of insurance required. Civilisation, eh?
In terms of illegal drugs, I've tried a couple of things over the years and found them perfectly pleasant and not at all addictive. So I'd be a hypocrite to throw a wobbly at the thought.
In my opinion, it would be far better if the government (and I'm talking specifically of the UK, where I live) legalised all recreational drugs – or at least decriminalised them to the extent that, like Amsterdam, you could get a joint or a space cookie openly and without fear of being arrested, in certain places where it is open and known about (it isn't actually legal in Amsterdam, but the Dutch are a pragmatic people). If you did this, you'd remove a huge amount of profit from organised crime, and also cut the link between the majority of recreational drug users and organised crime. It could possibly also help to break the links between parts of the sex industry and drugs.
Amsterdam also has an interesting approach to heroin use; if a user is registered with their local doctor, they get a fix every day. Free. (Obviously they get methadone or similar if they want to come off the drug) That might sound expensive, but the costs are saved in reduced crime to fund a habit, and also in a reduction of overdoses from bad or spiked H. Again, all this helps to break the link with organised crime.
Mind you, we could have cut the amount of opium on the world if we wanted to since the invasion of Afghanistan, but the allies (and the US in particular) has been largely clueless, has not really bothered to invest in or work hard at providing the kind of alternative crops and work for people in the country, and are far more interested in spending millions of dollars on a spanking new embassy in Kabul.
You'd think that they didn't really want to win the 'war on drugs'.
And before we forget, caffeine is a drug, as are alcohol and tobacco.