What is a crucial step to teach a client using a fentanyl transdermal patch?

The correct answer highlights an important safety practice related to the disposal of fentanyl transdermal patches. After the patch has been removed, it is essential to flush it down the toilet. This action is crucial because fentanyl is a potent opioid, and improper disposal can lead to accidental exposure, especially to children and pets, or environmental contamination. Flushing the patch ensures that it is disposed of safely and reduces the risk of misuse.

Other options present practices that either do not apply or are unsafe. Storing the patch in the refrigerator is unnecessary and could negatively impact the medication's effectiveness, while applying it to a hair-covered area could lead to reduced adhesion and inhibit the proper delivery of the drug. Using two patches simultaneously increases the risk of overdose and is not a recommended method for enhancing effectiveness. Proper education on the handling and disposal of fentanyl patches is crucial to ensure client safety and adherence to best practices.