Joe is a 42M who comes to see you to establish care after moving for work. He has a history of HTN, chronic pain from hand injuries at work, and opioid use disorder (OUD) maintained on buprenorphine-naloxone (SuboxoneⓇ, often referred to as “subs”) 16mg-4mg twice a day without any un-prescribed opioid use. He is a contractor and is able to function and do his job well on this dose and frequency of buprenorphine. You do a physical exam, review your clinic’s patient-provider agreement for prescribing controlled substances (which Joe signs), and order a urine drug screen. A week later, the urine test result returns and shows the norbuprenorphine metabolite in an expected 2:1 ratio with buprenorphine, consistent with Joe taking the buprenorphine as prescribed. You also see another finding on the gas-chromatography/mass spectrometry (GC/MS) urine test: a word you can’t pronounce, benzoylecgonine. A quick google search reveals that benzoylecgonine is pronounced ben-zoy-LEK-guh-neen and is a metabolite of cocaine.
- Tell Joe to do another urine sample because “we need to check something.”
- Call Joe and tell him that his cocaine use is a violation of the patient-provider agreement he signed so you cannot be his PCP anymore.
- Call the pharmacy and tell them to stop refilling the buprenorphine.
- Call Joe to discuss the results and ask about recent cocaine use.
We first want to congratulate Joe on not having any un-prescribed opioids/opiates in his urine and on being stable on buprenorphine, accomplishing his personal goals. In patients who are doing well on medications for OUD, the finding of a cocaine metabolite in the urine warrants a conversation. You would want to clarify this finding with Joe (“The urine test showed cocaine. What do you think about that?”) and explore his use and relationship to the substance. Does he see any connection (or interference) between the cocaine and the buprenorphine? Some patients with OUD use cocaine in a controlled (not chaotic ) way, and do not have problems because of their use; others have a co-morbid cocaine use disorder.
What if Joe says that this test must be wrong or must have been switched in the lab with someone else’s sample? In this case, the mass spectrometry test result can be checked for the other medications that Joe is taking. The qualities of this comprehensive assay make the risk of false positives absolutely minimal. If you need more information, you can connect with a lab medicine colleague to get the specs on your setting’s particular urine test. If the lisinopril, amlodipine, and acetaminophen he’s prescribed for his HTN and hand pain are in the urine in addition to the benzoylecgonine, then this is Joe’s urine sample. Typically, the GC/MS comprehensive test has a cut-off concentration of 100 ng/mL for benzoylecgonine to be reported and is reflective of cocaine use in the last few hours to days. More consistent and heavier use may cause the cocaine to be detectable for longer, as the initial rapid elimination of cocaine is followed by a slower phase that takes days to weeks (Nickley 2017).
In the follow-up for this case, Joe says that he used cocaine at a gathering with work buddies. This is not something that he does regularly, maybe once every 3 months. While it makes the fun last longer–especially if he has a beer at the same time—he doesn’t like that sometimes he gets anxious with the cocaine. He says he doesn’t have cravings for it; this is not like when he was “stuck on” heroin when he was younger.
You discuss that part of your work together is to continue an open discussion about the buprenorphine therapy and other substances that he uses. His cocaine use sounds controlled, without a use disorder, but with the anxiety he identified with use and other potential health consequences, you do not recommend continuing to use cocaine.
If, on the other hand, you learn from the conversation that Joe has a cocaine use disorder, you would then talk to him about treatment options for this specifically (look out for future PsychSnaps touching on this topic!), while still continuing the buprenorphine. Maintenance therapy for OUD (buprenorphine in this case) is continued as long as the patient’s goals are met (e.g. functioning at work or showing up for family), craving for opioids are controlled, unprescribed opioids/opiates aren’t used, and withdrawal isn’t occurring. These other signs/symptoms would all require their own conversation about adjusting the buprenorphine. One available monitoring guideline for patients on buprenorphine to check out for more information is the (not at all short) TIP 63 from SAMHSA.
Bottomline, as Joe is managing well with his OUD in remission, the finding of cocaine in the urine (and confirming use of cocaine with the patient) is NOT a contraindication to continuing to prescribe buprenorphine for OUD. In fact, this urine drug screen finding is a chance to discuss the role that cocaine plays in Joe’s life and offer support or further treatment as needed.
Nickley J, Pesce AJ, Krock K. A sensitive assay for urinary cocaine metabolite benzoylecgonine shows more positive results and longer half-lives than those using traditional cut-offs. Drug Test Anal. 2017 Aug;9(8):1214-1216. doi: 10.1002/dta.2153. Epub 2017 Mar 3. PMID: 28024167; PMCID: PMC5573903.
TIP 63 from SAMHSA: https://store.samhsa.gov/sites/default/files/SAMHSA_Digital_Download/PEP20-02-01-006.pdf
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