Not only am I off the bike for the forceable future, but the docs put me on painkillers where drinking is absolutely verboten!
Binners, what did he give you? You'll be fine on most things opiate based (e.g. codeine, DHC etc), but the paracetamol (if there's any in there) won't be great for your liver if you over indulge. You'll just need to keep it to a few pints or you'll be all over the place.
BUT, if it's tramadol, avoid alcohol like the plague.
NSAIDS (like diclofenac) are pretty grim with alcohol too.