Not that I can see, Q. I've had a nose round the Beeb's shop, and searching "pratchett" it came up with products for the nearest related word it could find........... "thatcher".
To be honest, I can't see there being much call for it. It's makes for pretty depressing viewing at times.
Having said that, Living with Alzheimer's is available on DVD from Amazon (UK at least).http://www.amazon.co.uk/Terry-Pratchett ... 103&sr=8-5
Some are born great, some achieve greatness and some have greatness thrust upon them.
The rest of us are a bit crap.