2 doctors weighed in:

What would cause a false negative urine drug test for fentanyl patches?

2 doctors weighed in
Dr. James Cain
Internal Medicine - Nephrology & Dialysis
1 doctor agrees

In brief: Errors

1. Not wearing the patch, an exhausted patch, a placebo patch 2.
The test was not specific for fentanyl 3. Lab error 4. Specimen misidentification.

In brief: Errors

1. Not wearing the patch, an exhausted patch, a placebo patch 2.
The test was not specific for fentanyl 3. Lab error 4. Specimen misidentification.
Dr. James Cain
Dr. James Cain
Thank
Get help from a real doctor now
Dr. Eric Weisman
Board Certified, Neurology
32 years in practice
9M people helped
Continue
108,000 doctors available
Read more answers from doctors