The FDA has a good point that Fentanyl is a "long term" opioid and should only be prescribed as such. But it is also the ultimate synthetic narcotic pain killer - 100X more potent than pure heroin (which is 10 times more potent the Morphine). Without it I doubt I would (or many others here) have survived the pain. I also took many showers with it on and never had a problem. It can cause an overdose if the patch is cut or damaged however so the user instructions must be followed VERY carefully. If is a safe and very effective drug when used properly. My neighbor, who recently died from pancreatic cancer was taking 5-100mcg patches - that IS the maximum dose. If you are using it just make sure that you follow the labeling to the letter and make NO changes in your dose rate without direct medical supervision or approval. Never quit this drug abruptly or "cold turkey" - it can cause convulsions and death. When it becomes time to stop taking it, you should get a phase out, tapering off, plan from your doctor.

The delivery mechanism is a permeable membrane that allows small amounts to be released transdermally (absorbed into the skin) and hence into the blood. It takes 24 hours to initiate a therapeutic level of the drug. After the first patch the pain management effect is very consistent.

It is not uncommon for other "short term" narcotics, such as Morphine to be used for "breakthrough" pain with it as well.

Morphine is the fastest acting, short term, pain killer. IV instantaneous, liquid about 4 minutes, oral about 30 minutes. Everything else takes at least an hour. If you are having to take Morphine frequently then they will increase the Fentanyl dosage, typically in 25 mcg increments.

Do NOT let the FDA advisory scare you if you are taking Fentanyl. On the home page there is a link to the NCCN Oncology Practice Guidelines and there is a special section on managing adult cancer pain if you are interested in the details.