Converting to transdermal fentanyl: avoidance of underdosing.

Background: Converting between the various opioid agents continues to be challenge for many practitioners. Specifically, variable recommendations for converting to the transdermal fentanyl patch may lead to confusion among clinicians and errors in dosing.

Objective: Our aim was to describe the inconsistencies among available opioid conversions with regard to transdermal fentanyl and to provide recommendations for safe and effective utilization of this product in patients with chronic pain.

Results: Available reports support the use of the morphine intravenous to oral ratio of 1:3 during the conversion to transdermal fentanyl product.

Conclusions: Underdosing is an often overlooked complication of switching to transdermal fentanyl. Current recommendations for converting to transdermal fentanyl do not reflect contemporary clinical practice and should be reevaluated.