This 2-point assessment can stave off problems.
1. Is the patient thin or febrile? Either condition can affect absorption of transdermal fentanyl, according to Mary Lynn McPherson, PharmD, BCPS, professor and vice chair in the Department of Pharmacy Practice and Science at the University of Maryland in Baltimore. Fentanyl is a very fat soluble drug, and thus may not work well for thin patients, although the mechanism for this isn't clearly understood, she says. On the other hand, if someone has a fever, he will absorb more of the medication, McPherson adds -- "that's true for any dermal application. The heat is going to make any drug come out of the patch more quickly."
2. Is the patient's pain stable? If not, McPherson advises against transitioning the person to transdermal fentanyl. "It's too difficult to chase a changing pain picture with a delivery system that takes three to six days to achieve a steady state."