In reply to NottsRich:
I had a laparotomy / stomach re-section 6 weeks ago (still not climbing or running again). I got morphine (self-administered gun thing - which I sat with most of the night, clicking away), IV paracetomol, which was v effective, and , urm, tramadol, also IV, and given before bed.
It drove me nearly bonkers. Weird dreams, whispering hallucinations, paranoia, inventing people talking outside my ward room, the lot. After 3 days, I was not happy, and on the 4th night, I got them to stop the IV drip of it halfway through, as I could feel myself slowly going utterly mad.
Hopefully, never again! But not as bad as overdosing on a Bhang Lassi in Rajaastan in the 1990s (worst drug experience ever).