Your doctor should also prescribe a short term, fast acting, narcotic such as morphine for breakthrough pain. That will also help while his therapeutic dose is built up with the patch. After the patches are started enough narcotic will be left in the blood that the pain relief will be continuous when changing patches. Fentanyl is very effective and one of the best long term pain meds out there.

There is also a transdermal morphine patch but Fentanyl is stronger.

Some doctors recommend changing the patches every 48 hours but, as Christine said, typically it is every 72 hours. Clean the skin with 99% alcohol before applying the patch - make sure that the skin is clean and dry as well.

Use caution showering with a patch on - try not to hit it directly with hot water. When applying a patch, never use the same spot and shave the hair first where it is going to be placed. The best place to place them are the shoulders or biceps.

Fentanyl is a very powerful and effective drug but can be dangerous if not used correctly. Read carefully the instructions for use.

12 mcg is a low dose, I didn't even know that they made a 12 mcg patch. Typically, in the US, patients are started on a 25 mcg patch and then the dose can be increased in 25 mcg increments until as much as 500 mcg, although that high a dose rate in not common for H&N cancer. The highest dose rate I have seen here is 250 mcg but , more typically 150-175 mcg (at the peak of pain). Never increase the dose rate unless instructed by your doctor.

Also NEVER stop Fentanyl abruptly! Work out a phase out plan with your doctor when it's time to quit.

Some instructions indicate flushing used patches down the toilet and also wearing gloves if the caregiver is applying them.

There has been multiple FDA warnings about Fentanyl and perhaps the doctors are being more conservative with their dose rates these days.