Self-reported adverse events associated with ∆8-Tetrahydrocannabinol (Delta-8-THC) Use

Abstract

Background: There is an expanding unregulated market for a psychotropic compound called ∆⁸-Tetrahydrocannabinol (delta-8-THC) that is being derived from hemp, but a summary of adverse events related to delta-8-THC has not been publicly reported.

Methods: This case series assessed adverse events reported by delta-8-THC users on the Reddit forum r/Delta8 and compared these to delta-8-THC AEs in the US Food and Drug Administration Adverse Event Reporting System (FAERS). Delta-8-THC and cannabis AEs reported in FAERS were also compared. The r/Delta8 forum was selected because it includes a large sample of 98,700 registered individuals who publicly discuss their experiences using delta-8-THC. All r/Delta8 posts were obtained from August 20, 2020, through September 25, 2022. A random sample of r/Delta8 posts was drawn (n = 10,000) and filtered for posts in which delta-8-THC users reported an adverse event (n = 335). FAERS reports that listed delta-8-THC (N = 326) or cannabis (N = 7076) as a suspect product active ingredient were obtained. Adverse events claimed to result from delta-8-THC use were coded using Medical Dictionary for Regulatory Activities to system organ class and preferred term categories.

Results: The absolute number of delta-8-THC adverse event reports (N = 2184, 95% CI = 1949-2426) and serious adverse event reports (N = 437; 95% CI = 339-541) on r/Delta 8 were higher than the adverse event reports (N = 326) and serious adverse event reports (N = 289) to FAERS. Psychiatric disorders were the most frequently cited system organ class in r/Delta8 adverse event reports, mentioned in 41.2% (95% CI = 35.8%-46.3%) of reports, followed by respiratory, thoracic and mediastinal disorders (29.3%, 95% CI = 25.1%-34.0%) and nervous system disorders (23.3%, 95% CI = 18.5%-27.5%). Anxiety (16.4%, 95% CI = 12.8-20.6), Cough (15.5%, 95% CI = 11.9-20.0) and Paranoia (9.3%, 95% CI = 6.3-12.5) were the most frequently cited preferred terms in adverse event reports. The overall prevalence of AEs reported for cannabis and delta-8-THC on FAERS were also similar when analyzed by system organ class (Pearson's r = 0.88).

Conclusions: The findings of this case series suggest that most of the adverse events reported by delta-8-THC users are like those reported during acute cannabis intoxication. This finding suggests that health care professionals follow similar treatment and management protocols, and that jurisdictions should clarify whether delta-8-THC can be sold as a hemp product.

Keywords: Adverse Event; Cannabinoid; Delta-8-tetrahydrocannabinol; Reddit.

Fig. 1

Data collection scheme for adverse events associated with delta-8-THC on Reddit and delta-8-THC and cannabis on FAERS. Abbreviations: AE = adverse event; r/Delta8 = a topically-focused Reddit forum known as a “subreddit” dedicated to discussions of delta-8-THC; FAERS = Food and Drug Administration Adverse Event Reporting System; MedDRA = Medical Dictionary for Regulatory Activities

Fig. 2

The number of adverse events associated with delta-8-THC reported on FAERS and estimated number of adverse events associated with delta-8-THC reported on the Reddit delta-8-THC forum r/Delta8 by quarter. Abbreviations: r/Delta8 = a topically-focused Reddit forum known as a “subreddit” dedicated to discussions of delta-8-THC; FAERS = Food and Drug Administration Adverse Event Reporting System

Fig. 3

The overall prevalence of adverse events associated with delta-8-THC reported on r/Delta8 and FAERS were similar when analyzed by MedDRA System Organ Class. Note: each dot is the number of all AE reports associated with delta-8-THC labeled with each MedDRA SOC in FAERS (y-axis) or r/Delta8 (x-axis) divided by the total number of AE reports associated with delta-8-THC on FAERS (y-axis) or r/Delta8 (x-axis). For instance, 29.3% of all delta-8-THC AEs reports in the r/Delta8 sample and 27.9% of all delta-8-THC AE reports in FAERS were categorized as respiratory, thoracic, and mediastinal disorders (highlighted in orange). The line represents the linear correlation in the prevalence of each SOCs between the two samples and is summarized with a Pearson’s r statistic. Abbreviations: AE = adverse event; r/Delta8 = a topically-focused Reddit forum known as a “subreddit” dedicated to discussions of delta-8-THC; FAERS = Food and Drug Administration Adverse Event Reporting System; MedDRA = Medical Dictionary for Regulatory Activities; SOC = MedDRA System Organ Class

Fig. 4

The overall prevalence of adverse events associated with delta-8-THC and cannabis reported on FAERS were similar when analyzed by MedDRA System Organ Class. Note: each dot is the number of all AE reports associated with delta-8-THC (y-axis) or cannabis (x-axis) in FAERS labeled with each MedDRA SOC divided by the total number of AE reports associated with delta-8-THC or cannabis respectively. For instance, psychiatric disorders were the most prevalent AE reported for both delta-8-THC and cannabis cases, being reported by 66.0% of all delta-8-THC AEs reports and 65.2% of all cannabis AE reports in FAERS (highlighted in orange). The line represents the linear correlation in the prevalence of each SOCs between the two samples and is summarized with a Pearson’s r statistic. Abbreviations: AE = adverse event; r/Delta8 = a topically-focused Reddit forum known as a “subreddit” dedicated to discussions of delta-8-THC; FAERS = Food and Drug Administration Adverse Event Reporting System; MedDRA = Medical Dictionary for Regulatory Activities; SOC = MedDRA System Organ Class