Heres a mad qeustion my mate asked me last night ,how do painkillers such as paracetamol know where your pain is in the body ? i said i dont know im not a medical person so over to you guys on this one ? Ian
The wiki answer is almost right. Aspirin and paracetamol work on the whole body, reducing inflammation where they find it. Codeine (aka methyl morphine) works like the wiki says, by blocking pain receptors in the brain. You used to be able to buy codeine on its own but now it only comes combined with paracetamol as cocodamol.
I'm not sure about ibuprofen. It's an entirely man-made drug, built up atom by atom in a research lab. I always thought it was an improved version of paracetamol - which is itself an improved version of aspirin - but you can take it in addition to codeine and paracetamol. Somebody around here must know how it works. I'll ask a radiographer tomorrow.