Doctors often use urine tests to make sure patients taking medication for opioid addiction are sticking with treatment. A new study suggests they may be missing some cheaters.
Nearly 8% of these patients sometimes spike their urine by adding their treatment medicine, buprenorphine, to the samples. Such spiking may go unnoticed by doctors who use rapid tests instead of more sophisticated lab tests that can reveal who's cheating.
"These patients are at particularly high risk for opioid overdose, as they are not receiving the protective effects of buprenorphine," said Dr. Jarratt Pytell of University of Colorado School of Medicine, who led the study published Wednesday by JAMA Psychiatry.
About 2.4 million U.S. adults are prescribed this gold standard medication for opioid addiction. It works by preventing craving and is often paired with counseling and other support. With overdose deaths climbing, Congress recently made it easier for more doctors to prescribe buprenorphine, which is sold under the brand name Suboxone.
In the study, researchers looked at more than 500,000 urine test results from Millennium Health, a large laboratory. The tests had been ordered by doctors from 2017 through April 2022.
Less than 2% of samples — from 7.6% of patients — had evidence that patients directly added buprenorphine to the urine specimen. Spiking was indicated by a low amount of a substance produced as buprenorphine breaks down in the liver.
Suspicious specimens were more likely to be collected in primary care doctor's offices than in specialty treatment clinics. And patients with evidence of spiked samples were more likely to test positive for heroin or fentanyl use.
Doctors shouldn't cut off patients who cheat, Pytell said. That could lead to overdose. Instead, a suspicious result should prompt a frank discussion and possibly a higher level of care. Doctors should discuss whether patients are struggling with inadequate housing, mental health issues or financial strain.
"When patients tamper with their urine specimen it often indicates that they are unstable in their recovery and they could use more help," said study co-author Brendan Saloner of Johns Hopkins Bloomberg School of Public Health. "Unfortunately, many patients are punished either by their program or by some legal authority, and they therefore have reasons why they may want to mask that they are not taking their buprenorphine as prescribed."
Dr. Kim Dougan, a primary care doctor in the Seattle area, has treated hundreds of patients with buprenorphine.
"People not only get their life back, they get their jobs back, they get their families back," Dougan said. Her new patients take a weekly urine test that is sent to a lab. Long-term, stable patients do an annual test.
If lab results look suspicious, she brings it up with the patient, but doesn't punish or judge.
"My job is to say, 'What's going on here?'" Dougan said. "Being open and nonjudgmental is important."