Oxycodone may impair the brain over time:
 

This is an interesting article on the consequences thought to
be happening with long term oxycodone use:

http://psychcentral.com/news/2014/11...ges/77442.html

There are many Google entries on "brain damage opiates" and they have been growing over the years.

It is a factor needing to be decided for long term chronic pain control. Some may accept this, and others not...but having the information may help make the decision.