Make sure you get all information sheets and inserts from your pharmacist, and read them through carefully before applying your first patch. If you have any questions/concerns, then is the time to bring them up with either your doctor (by phone -- I don't know if s/he's your PCP or specialist or what) or the pharmacist (who may be easier to reach than your doctor). Not all doctors are as aware as they might be of the meds they prescribe.

You can supplement this with information from credible sources on the web. (IMO, Wiki is an OK starting point.)
butrans patch for pain
Also try some of the related searches at the bottom of the first search page.

Doc