I am on 12m fentanyl patches and six perc 5s for breakthrough pain. I am getting a shoulder replacement in 3 months. The meds make me able to have a normal life and not have to lay in bed 24/7. I am concerned about physical dependenCE and have been changing the patch every 6 days instead of 3 to try and do whatever I can to minimize withdrawal when I have to get off these. Do you think this is a good idea?