@iL Dottore Tramadol? The Devils drug, as far as I'm concerned. I did my back in once and was prescribed the big T, nausea and incomprehension for several days until I stopped taking the stuff. No wonder your Vogon poetry was so spaced out...
It might have been painkilling, but only because I was on a little fluffy cloud and daren't move in case I puked.
Other stuff was prescribed, with less unpleasantless, and my back gradually calmed down.