Fentanyl 25 mcg/h questions?

[trickfire]

Hi a friend of mine has obtained some 25 mcg/h fentanyl for 72 hrs transdermal system. He is used to self mediating with 60-90 mg of oxycodone a day, how should they be used. I know there are plenty of threads with conversion discussions and other ROA's, yet I have not found the answer I'm looking for to help him out. Is this is a safe amount, or is it safe to leave the patch on for however long and if how long? I hope the content of this question is not deemed stupid, because we honestly have tried to find the right conversion, but have not had any luck. Please help, and thanks