The Case for Expanded Drug Screening Panels

Drugs of abuse (DOA) testing is no longer just about synthetic cannabinoids. Maryland-based drug abuse researchers who teamed up with two area hospitals found that illicit street drug formulas had evolved to the point that they contained multiple psychoactive substances. Their study results have significant implications for clinical labs and emergency physicians in developing DOA testing panels and interpreting DOA test results.

“Our findings indicate that there is widespread polydrug use occurring among persons using drugs, most of which cannot be detected through standard drug tests,” Eric Wish, PhD, the study’s principal investigator and director of the Center for Substance Abuse Research (CESAR) at the University of Maryland, College Park, College of Behavioral and Social Sciences, told CLN Stat. CESAR recruited emergency physicians from University of Maryland Medical Center Midtown Campus (UMMC) Baltimore and the UM Prince George’s Hospital Center in Cheverly, a suburb of Washington, D.C., to assist with the drug testing study.

Use of some common substances are unlikely to change, such as alcohol, cocaine, and cannabis. However, other newer substances are always coming out, observed Zachary D.W. Dezman, MD, a UMMC Midtown emergency physician. “Synthetic cannabinoids are but one example. Even heroin, which is easily detected in urine along with morphine, is now being replaced by fentanyl, which has a different chemical structure and is not detected on standard urine drug screens,” Dezman told CLN Stat.

To conduct the research, the Armed Forces Medical Examiner System laboratory in Delaware received 106 urine samples from UM Prince George’s and 69 from UMMC Midtown, analyzing them for 26 synthetic cannabinoids, 59 designer drugs, and 84 other illicit and prescription drugs. Investigators expected to see a high yield for synthetic cannabinoids—yet only one specimen tested positive, a sign that these drugs were evolving into different formulas undetectable on urine tests. Even when the lab expanded its tests for synthetic cannabinoids from 26 to 46 metabolites, just 25% tested positive for this substance. In up to a third of all specimens at each hospital, investigators found a new psychoactive substance that wasn’t a synthetic cannabinoid.

Although marijuana was the most common substance found in samples from both hospitals, two-thirds of the patients tested positive for multiple substances. Patients at UMMC Midtown tested positive mainly for marijuana, although fentanyl and nonfentanyl opioids were found in 28% and 51% of the samples, respectively. At UM Prince George’s, the illegal hallucinogenic drug PCP emerged as a substance of concern, showing up in 47% of the specimens.

“These drug use patterns are not surprising because PCP use is well documented in Prince George’s County … as well as in the neighboring city of Washington, DC. UMMC is located in Baltimore City, an area known to have a high prevalence of opioid use,” the authors of the report explained.

What was perplexing is the substances found on the tests often didn’t match up to the drugs the patients said they took. “We had cases where the doctors thought so, the patient thought so, but urinalysis showed no use of synthetic cannabinoids,” said Bradford Schwartz, MD, an emergency physician at UM Prince George’s, in a statement.

This report demonstrates the need for collaborative research teams that conduct regular monitoring of drug use trends. This would assist physicians who treat patients suffering from substance abuse, Dezman said. Emergency physicians have gotten used to treating opioid overdoses. “Patients should be told when and if they are using something as dangerous as fentanyl. Similarly, an absence of data regarding the incidence and prevalence of use prevents public health officials from making informed policy decisions,” he said.

Clinical laboratories in light of these results might want to consider expanding their panels to include screening for synthetic drugs, particularly synthetic cannabinoids and synthetic opioids, such as fentanyl and its analogs, Wise said. Dezman said his facility is developing the ability to do regular fentanyl testing in its emergency departments in Baltimore. He is also conducting further analysis on the study results.

CESAR in the meantime is tracking drug trends through multiple projects. It’s the coordinating center for the National Drug Early Warning System (NDEWS), which is funded by the National Institutes of Health’s National Institute on Drug Abuse. CESAR oversees NDEWS’ Drug Outbreak Testing Service, which allows public health agencies to submit at no cost up to 20 urine specimens for expanded drug testing for up to 240 drugs to identify the drugs being used by their population. CESAR is also conducting expanded urine testing as part of several larger studies funded by the Office of National Drug Control Policy to monitor drug use trends in criminal justice and public health programs across the United States. “In addition, important information can be gathered from toxicologists, particularly from within the geographic regions where the urine testing is to be conducted,” Wise said. 

The original article please refer to AACC CLN News:　https://www.aacc.org/publications/cln/cln-stat/2018/september/20/the-case-for-expanded-drug-screening-panels