Toxicology Rounds: Your ED Patients Are Likely Using Delta-8-THC : Emergency Medicine News

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Toxicology Rounds

Toxicology Rounds

Your ED Patients Are Likely Using Delta-8-THC

Gussow, Leon MD

Emergency Medicine News 43(8):p 18, August 2021. | DOI: 10.1097/01.EEM.0000771128.03134.48
    Delta-8-THC, cannabinoid, Cannabis legalization:
    Delta-8-tetrahydrocannabinol, left, and delta-9-tetrahydrocannabinol are similar except for the location of the double bond.

    The Michigan Poison Center issued a warning this past April about delta-8-THC, a little-known cannabinoid found in hemp and marijuana that has replaced cannabidiol (CBD) as the most rapidly growing segment of the unregulated hemp market.

    Virtually unknown two years ago, delta-8-THC can now be purchased over the counter in many vape and smoke shops, gas stations, and convenience stores, available in all the familiar forms: smokable flower, tinctures, edibles, vaping cartridges, and concentrates.

    The story behind this involves massive competing economic, political, scientific, cultural, and legal interests. It's better than even odds that some of the patients you're seeing are using delta-8-THC in some form.

    What Is Delta-8-THC?

    The National Cancer Institute describes delta-8-THC as an analogue of delta-9-THC with antiemetic, anxiolytic, appetite-stimulating, analgesic, and neuroprotective properties. ( Structurally, delta-8 differs from delta-9-THC only by the placement of a single double-bond. (Figures.) Found in very small concentrations of marijuana and hemp, it is sometimes called THC lite (or weed lite) or diet THC (or diet weed) because its effects are similar to but somewhat less potent than those of delta-9-THC.

    Delta-8 has not been studied extensively, and limited anecdotal reports from poison centers and users indicate that these side effects include tachycardia, dizziness, fatigue, and changes in visual perception and sense of time. Some users claim that the high produced by delta-8-THC is similar to that of marijuana but with less anxiety and paranoia.

    The legalities of delta-8-THC change from month to month and from state to state. Hemp is defined as the Cannabis sativa plant containing no more than 0.3 percent delta-9-THC by dry weight. The Agriculture Improvement Act of 2018, known as the farm bill, legalized hemp and its derivatives and extracts. This was a gift to the large hemp farming industry, which was finding itself with an oversupply of product at a time when interest in CBD concoctions was drying up. The developing legal Cannabis industry, however, sees delta-8 as cheaper competition minus the hassles and expense of testing, regulation, and taxation.

    Inevitably, the Drug Enforcement Agency saw the situation differently. It noted that commercial delta-8-THC is generally not isolated from hemp because the isomer occurs in such small concentrations in the natural plant that this would not be financially viable. Rather, delta-8-THC was synthetically manufactured by treating hemp-derived CBD with solvents and acids. The DEA issued an interim final rule in August 2020 stating that all synthetic cannabinoids were Schedule I drugs and under its jurisdiction. Multiple lawsuits are challenging that. A good way to keep up with this evolving legal situation is to follow the useful Canna Law Blog. (

    Possible Medical Uses

    Delta-8-THC may have medical potential. An Israeli study pretreated eight children with hematologic malignancies with delta-8-THC prior to administering chemotherapy that was expected to produce significant emesis. None of the children vomited, and the authors reported no significant side effects from 480 treatments in those patients. Unfortunately, there was no control group for comparison, and the authors did not follow up with more extensive research despite the promising results. (Life Sci. 1995;56[23-24]:2097.)

    Whether exposure to delta-8-THC causes a urine drug screen for cannabinoids to turn positive has not been studied. The structures of delta-8 and delta-9-THC are so similar that one would expect cross-reaction to occur, but this has not been established scientifically.

    I enlisted the assistance of an acquaintance as a (very) preliminary pilot study. Immediately after producing a urine sample negative for THC using a home screening test, the subject ingested a 5 mg delta-8 gummy. A subsequent urine sample obtained approximately 140 minutes after ingestion produced a clearly positive result on the home screening test. (Confirm Biosciences.)

    Does this mean that delta-8-THC turns a urine drug screen for THC positive? Not conclusively. The limitations of the study—aside from the n of 1—include our inability to verify that the edible contained only pure delta-8. The gummy was supported by an extensive analytic report purporting that it contained no delta-9-THC, but I was not able to establish that the lab was accredited or certified or even that it existed.

    The U.S. Cannabis Council, a trade group representing the legal Cannabis industry, recently tested 14 samples of delta-8 products purchased in several different states, and all contained levels of delta-9-THC above the legal 0.3 percent limit for hemp. The highest level tested was more than 10 times that legal limit.

    Is It Safe?

    Not necessarily. Delta-8-THC produces psychotropic effects similar to those of Cannabis, so exposure may impair cognitive function and other neurological processes, increasing the risk of a crash when driving a car or operating other dangerous machinery. The delta-8-THC market is unregulated, and products may not undergo thorough analytical testing, creating a risk that the product may be contaminated with heavy metals, pesticides, mold, or other toxic substances.

    Given our recent experience with e-cigarette or vaping product use-associated lung injury (EVALI), I would think that using unregulated delta-8 vape cartridges may be especially risky. Toddlers have also presented to the hospital with sedation, agitation, and hypotension after ingesting delta-8 gummies.

    Emergency physicians should suspect that patients may have been exposed to delta-8-THC, which they may not associate with Cannabis. If appropriate, ask the patient specifically about use of delta-8. Users should be cautioned not to drive within 10 hours of use and to keep edibles in a place not accessible to children. I would also recommend that patients be advised not to use delta-8 vape cartridges at all.

    Dr. Gussowis a voluntary attending physician at the John H. Stroger Hospital of Cook County in Chicago, an assistant professor of emergency medicine at Rush Medical College, a consultant to the Illinois Poison Center, and a lecturer in emergency medicine at the University of Illinois Medical Center in Chicago. Follow him on Twitter@poisonreview, and read his past columns at

    Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.
    • blemberg9:06:29 PMDr. Gussow: I enjoyed your article on delta-8-THC. Yes, it does screen positive on Immunoassays for THC (both delta-8 and delta-9 and some cheaper assays, even CBD!). The only way that one can distinguish the difference is using LCMSMS (liquid chromatography tandem mass spectrometry). We have a cannabinoid LCMSMS run here that separates CBD, delta-8, delta-9, and other cannabinoids (mainly in oral fluid samples). We have been reporting delta-8 (with and without delta-9) in Child Protective Services clients in Indiana and Ohio since January 2021. It will be interesting to see how the courts in these states handle these positive delta-8 tests. We also are putting delta-10 and THC-O on the LCMSMS instruments in the next two weeks (both of those should “screen” positive for THC using Immunoassays too). Thank you for sharing more information on delta-8