" FDA ALERT [7/2005]: Narcotic Overdose and Death
FDA is looking into reports of death and other serious side effects from
overdoses of the narcotic fentanyl in patients using the fentanyl
transdermal skin patches for pain control. Directions for using the fentanyl
skin patch must be followed exactly to prevent death or other severe side
effects that can happen from using too much (overdosing) fentanyl. These
directions are provided in the patient package insert."

Google is your friend.

It doesn't even have to be an "overdose" as we commonly think of it.
There are different strengths of fentanyl transdermal patches. If a
patient is "opiate naive", meaning he/she
has not built up a tolerance to pain medication, like an advanced-stage
cancer patient
might, the smallest patch could send him/her into respiratory
depression or respiratory arrest. Someone not naive to narcotic
analgesics, can apply 3-4 patches of the highest strength, and will not
suffer any adverse drug reactions.

Also, users or caretakers who remove patches (especially if the patch
has been on less than three days), should cut the patch in half and
dispose of it where it would be difficult to obtain. Some people in
pain, who also knows the ropes, will seek out thrown away intact
patches and may put themselves at risk.

Physicians not familiar with the patch, have ordered it daily - e.g.
"Apply one 300 mcg patch daily". The half-life of the drug in this
dosage form, is such that enough active drug remains in the patch to
allow a it to deliver pain relief for 72 hours. If ordered more
frequently then every 3 days, the drug can accumulate in the body.
(Dosing every two days may be possible in patiens with chronic,
intractable pain). A pharmacist or a nurse should question an order for
a fentanyl patch to be applied more frequently than every 3 days.