What Causes Back Pain And Depression While On Duloxetine?

Posted on Tue, 5 Sep 2017

Question: My husband got a "high" Benzodiazepines result on a urine test he took on 7/31. He DOES NOT USE ANY KIND OF STREET DRUGS!! He wears a 50mcg Fentynal patch that he changes every 3days. The next day, roughly 12hrs later, a second urine test showed he had a "high" Benzodiazepines result and a "high" Cannabinoids result. He DOES NOT USE MARIJUANA!!! We are wracking our brains trying to figure out what happened to get these results. He is 77 years old and has had back trouble since 1992. After surgery then he was told he has degenerative disc problems. He is on several meds for back pain, hiatal hernia, depression and sees a mental health doctor about every 4-6 weeks because of the Fentanyl patches and Duloxetine (90mg). He is seeing a Pain Specialist right now trying to get off the patches but with these results he may loose the privilege of their benefit before we can find another fix for his pain. Can you give us some ideas of what might have made these levels go up. His urine test in February 2017 were normal as has all of his others since he went on the patches in March 2006. I know how suspicious this looks but I assure you he is not using marijuana or any other unprescribed meds.

Answered by Dr. Dr. Michelle Gibson (3 hours later)

Brief Answer:
false positives can occur

Detailed Answer:
HI, thanks for using healthcare magic

There are medications that can cause false positive results to occur.

Medications that can cause false positive for cannabinoids are:(1) NSAIDs- some medical studies suggest that NSAIDs such as naproxen or ibuprofen can cause falsely positive results

(2)dronabinol-used to treat nausea and vomiting

(3)pantoprazole- one of reflux medications

Medications that can give false positive for benzodiazepines are: (1)the antidepressant sertraline
(2)Some nsaids such as naproxen, oxaprozin, fenoprofen, tolmetin have been reported to cause problems as well

Further testing by GC MS (gas chromatography, mass spectrometry) would give definitive accurate results.

The initial testing is a screen test but additional testing can be done.

i hope this helps, feel free to ask any other questions

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Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar