Is Oxycontin the same drug as Fentanyl?
No, but, they are both opiates, and are cross-tolerance with each other. But Oxycontin is an extended release pill and fentanyl is most commonly prescribed as a time-release gel-containing patch. But they're two completely different drugs.
No - they are 2 completely separate drugs. OxyContin is the time release version of Oxycodone, and typically lasts from 7-12 hours. Duragesic / Fentanyl transdermal patches are timed release fentanyl over a 48-72 hour period. Its release is regulated by body heat. It is a much more reliable and steadier drug than OxyContin, in that it doesn't wear off as fast, and it lasts a lot longer.
In general, no. This is because OxyContin is itself a timed-release opiate, and many patients who move up to Fentanyl patches have already been using OxyContin for some time and have become more tolerant to it. Fentanyl patch patients will typically use oral Oxycodone (usually Percocet) for a breakthrough medication.