What are the latest significant trends in designer drug use?

While patterns of drug abuse vary by region and with time, a review of reliable resources indicates the following trends. Illicit fentanyl and fentanyl analogues continue to plague our society. In Q1 2023, the U.S. Drug Enforcement Agency (DEA) seized over 16 million fentanyl pills and 2,700 lbs. of fentanyl powder. Drug dealers continue to use pill presses to form counterfeit tablets that are nearly identical to pharmaceutical oxycodone tablets, alprazolam bars, and others. According to forensic laboratories, the amount of fentanyl in counterfeit tablets from the same batch may range from trace to lethal amounts.

If that is not concerning enough, in late 2022, DEA published a warning that 23% of illicit fentanyl powder seized by the agency was adulterated with xylazine. Xylazine is an alpha-2 agonist used as a veterinary tranquilizer, but is not approved for human use, nor scheduled as a controlled substance. It has been associated with many overdose deaths in the past and is making a resurgence. Xylazine is known to cause central nervous system depression, respiratory depression, hypotension, and bradycardia. Repeated injection of xylazine-adulterated drugs is associated with necrotic skin ulcerations. Routine immunoassay screens do not detect xylazine, but one company, BTNX, offers lateral flow test strips for forensic use.

The Center for Forensic Science Research & Education also reported that, in Q1 2023, bromazolam (171 cases) led the list of designer benzodiazepines, whereas pentylone (112 cases) and N,N-dimethylpentylone (166 cases) topped the list of stimulants. The synthetic cannabinoid MDMB-4en-PINACA (37 cases) was the most abundant cannabinoid, whereas more than 30 cases involving three new opioids, isotonitazene metonitazine, and N-desethyl isotonitazene, have been reported.

The National Poison Data System reported that in Q1 2023, toxic exposures from edible THC products topped the list after intentional ingestion (www.aapcc.org/national-poison-data-system). This may be due to perceived safety after the legalization of THC in many states, but other factors also contribute. The drug absorption phase from edible products is prolonged compared to other routes of administration, which may lead to overdose if an individual continues to consume the product after no psychological effect is perceived within a few minutes. Edible THC products also can be similar in appearance to gummy bears and other commercial candies, which contributes to their consumption by children. In 2021, more than 4,300 children 0-12 years of age were treated in emergency departments after consumption of THC edibles. These patients often present with ataxia, confusion, vomiting, and hallucinations.

How can labs stay abreast of these trends?

All laboratories can monitor reliable data sources such as those listed above. Laboratories can also increase their breadth of testing by incorporating a fentanyl immunoassay into their drug testing regimen. Several fentanyl immunoassays are commercially available, each with their own sensitivity and selectivity toward fentanyl analogues.

Laboratories offering comprehensive toxicology services should strive to keep their mass spectral databases updated by incorporating data from commercial standards of the most common drugs. These laboratories can use online mass spectral search tools such as those from Cayman Chemical Company (www.caymanchem.com/forensics/search/drugId) and the Scientific Working Group for the Analysis of Seized Drugs (www.swgdrug.org/ms.htm).

What else do labs need to know?

Chromatographic techniques coupled with mass spectrometry are the most reliable methods for identifying novel substances. Instruments that can perform online mass spectral matching will be most effective for identifying new designer drugs. Laboratories should also be aware that a DEA toxicology testing program will analyze biological specimens suspected to contain designer drugs (www.deadiversion.usdoj.gov/dea_tox/index.html), although the turnaround time for results may require several weeks.

Patrick Kyle, PhD, DABCC, DABFT, is director of clinical chemistry and toxicology labs and a professor of pathology at the University of Mississippi Medical Center in Jackson, Mississippi. +Email: [email protected]