A study of 1 million urine drug tests processed in the U.S. by the specialty laboratory Millennium Health suggests that users of cocaine and/or methamphetamine are increasingly also using illicit fentanyl and are at risk of overdosing.
Results were published by Leah LaRue, associate director of clinical affairs at Millennium Health, and colleagues in JAMA Network Open on April 26.
The researchers randomly selected urine drug tests performed on 1 million patients between 2013 and 2018, excluding specimens from those who had been prescribed fentanyl. Testing was done with liquid chromatography-tandem mass spectrometry.
In 2013, 0.9% (n = 84) of tests that were positive for cocaine were also positive for fentanyl, compared with 17.6% (n = 427) in 2018, a statistically significant increase.
The same trend was observed for methamphetamine. In 2013, 0.9% (n = 29) of tests positive for methamphetamine were also positive for fentanyl, compared with 7.9% (n = 344) in 2018, also a statistically significant increase.
The results may suggest that users of cocaine and methamphetamine are also increasingly using fentanyl; however, it also could be that fentanyl is being added to the supply of stimulants by drug trafficking organizations, the authors suggested.
Testing had been ordered by a range of practice types, including substance abuse treatment centers and primary care providers.
"Clinicians need to be aware that patients presenting for treatment of suspected drug overdose or substance use disorder may have been exposed, knowingly or unknowingly, to multiple substances, including the combination of stimulants and opioids," the authors advised.