I had sciatica for a while, my girlfriend said her sister had a bad back and had some pain killers (which turned out to be Tramadol) I could have while I waited for an appointment at the doctors. I took one and it seemed to do nothing, so a few hours later took another. I was out of it for a whole day, they made me immensely tired, and I slept for nearly 24 hours.
On the other hand I am fine with Cocodamol.