I had it prescribed to me for post-tonsillectomy management. It's called Endone in Australia.
I can't believe the grasp it has on me. I only took it once during the post-op period and haven't taken it since, but I'll never forget how relaxed I was.
Whenever I'm stressed I'm tempted to take it again just to calm down.
Fortunately, willpower, morals, and not having an addictive personality have prevented me from taking it again. But I definitely understand how it can become addictive.