Food and Drug Administration is currently reviewing a petition that raises concerns over the “significant harm” a device used to test for marijuana metabolites could cause employers and law enforcement if they administer the drug tests under the false impression it shows a person has actually used marijuana rather than being exposed secondhand smoke.
Harmed Americans for Reform in Medical-Device Safety – a non-profit focused on medical-device safety, founded by Northeastern Law Center and Tufts Medical Center experts – submitted the petition to FDA last week. HARMS doesn’t focus exclusively on cannabis, but it said that an FDA approved cannabinoid testing device developed by the Psychemedics Corp. raises serious questions the FDA should answer.
“Our petition requests that the FDA require clearer labeling to specify that the device can be used to detect only the presence of cannabinoid metabolites in hair and cannot be used for ‘identifying marijuana use,'” as the label implies,” HARMS’s Hooman Noorchashm said in a press release. “If firms use this 510(k) device for the express purpose of ‘identifying marijuana use,’ they are not using the device properly.”
The hair test is unique because it can be a good indicator of cannabis use. Secondhand smoke could also lead to a positive outcome. HARMS advises FDA to use its authority and revise labeling requirements for the device to make this point clear.
Experts said that changing the labeling was “especially important” since “the Psychemedics is used to detect marijuana usage in insurance and employment contexts and by federal, local, and state law enforcement agencies.”
Cannabinoid-metabolites can be detected in hair both in cases of intentional use or accidental exposure, according to the FDA petition. “So while hair testing can detect cannabinoids, it cannot definitively confirm marijuana use because ‘external contamination’ is always possible.”
Other standard THC test can definitively prove past cannabis use, but “hair tests of the type used in the Psychemedic Device detect THC-COOH for a longer time period (months), and face additional challenges including false positives due to passive exposure (e.g. inadvertently inhaling marijuana smoke), and variability in cannabinoid inclusion because of hair types, hair treatments and growth rates.”
It says: “Given that hair testing is not reliable to determine marijuana use accurately, the FDA needs to evaluate the Psychemedics or cannabinoid labeling on hair testing.” The concerns raised have a real impact. The Psychemedics device, for example, is often used by law enforcement officials.
Consumers (employers), who may mistakenly think that positive test results are proof of intentional marijuana use even though they may only reflect exposure to marijuana through passive means, may believe this falsely. The misunderstanding could cause serious harm to people who are considered marijuana users. This can lead them to receive inappropriate medical attention or be denied employment. “The FDA should take these requested actions to make sure that users and consumers understand the limitations on the Device.”
HARMS’s David Simon said that the ‘labeling and instructions for use are a crucial component of a device that is supposed to provide accurate information to consumers and users.”
He said that the current instructions are unclear and don’t achieve their goal. The livelihoods of many people could be in danger if they do not use the test correctly.
The petition asks FDA to recommend or order Psychemedics to revise the device’s instructions for use to read: “The Psychemedics Microplate EIA for Cannabinoids in Hair is an enzyme immunoassay (EIA) for the preliminary qualitative detection of cannabinoid metabolites in hair using a 11-nor-9-Carboxy- Δ9-THC calibrator at a cut off of 10 pg/10 mg hair.”
The FDA suggests an alternative: “provide a warning on the Device that does not indicate whether any test subjects used marijuana. It only detects cannabinoid-metabolites present or absent in hair. This could occur without the subject using cannabis.”
MEDCAN24 contacted Psychemedics, asking for a statement. A representative wasn’t available at the time.
The complexity of cannabis drug testing policy has also increased in recent years as the legalization movements continues to grow.
A Rutgers University professor of law published, in July, an article examining the “inadequate” nature of roadside tests used widely by U.S. police departments to determine marijuana impairment. He called on policymakers to adopt a scientifically sound approach to transport safety, and to rely less on the ostensible expert knowledge of law enforcement.
Another wrinkle has emerged in the debate over cannabis testing: According to a researcher at the U.S. Department of Justice, it is unclear whether THC levels can be used as a reliable measure of impairment.
Last October, a study preprint posted on The Lancet by an eight-author team representing Canada’s Centre for Addiction and Mental Health, Health Canada and Thomas Jefferson University in Philadelphia identified and assessed a dozen peer-reviewed studies measuring “the strength of the linear relationship between driving outcomes and blood THC” published through September 2023.
The issue was also examined in a federally funded study last year that identified two different methods of more accurately testing for recent THC use that accounts for the fact that metabolites of the cannabinoid can stay present in a person’s system for weeks or months after consumption.
Martin Alonso is the photographer.