Interesting you say that Jack... I was in hospital a few years ago with a burst appendix, and when I came round I was put on a morphine drip to self medicate - a push of the button when you needed it - and I seriously thought that I was going mad - I couldn't sleep at all, and at nights I kept thinking I was on the Star Ship Enterprise, and the elderly gentleman in the next door bed was trying to get his cat in with a saucer of milk! It sounds funny now, but it was scarey at the time. Afterwards I injured my back and have been on tramadol ever since - they are the only things that take the edge off the pain, and I seem fairly ok with taking them now - I can't take iboprufen, which used to be my painkiller of choice, but I've had liver problems in the past so can't take them and coedine makes me sick.