There is so much more to it than just the cost of the morphine. Drug seekers have an enormous impact on the costs to society (though I cannot speak for the system in the UK, only in the US). Who do you think pays for the ER visits for all of these people? Most of them will have medicaid (which the taxpayers pay for) or no insurance (the hospital will then pass the costs on to those who can/will pay their bills). Then there is the impact they have on the ER itself. They take up a bed that could be used by a person who really needs it. They take up the time and resources of the doctors, nurses, tech, etc that take care of them. When they call an ambulance they are taking up a ambulance that could be used by someone who truly needs it (and they likely will not pay for it). The US healthcare system is busting at the seams and is ready to collapse. These people are only making the situation worse. Their impact is much more severe than just the cost of the vial of morphine.
I am not saying not to treat people for pain (read some of my previous posts and you will see I advocate just the opposite), but when you have been in the field long enough you can spot BS coming through the door. I explain to these people that the ER is an inappropriate place to treat their chronic pain problems. I also tell them that it would be inappropriate for me to treat their chronic pain with the 4mg of Dilaudid (which I feel is one of the worst drugs ever created) that they ask for. So, while it may not seem like a big deal to give a drug seeker their hit once in a while, keep in mind that there is a much larger picture than what you have to deal with in the back of the of the ambulance.
I'll step off of my soapbox now and return you to your previously scheduled thread.