Overbaked: assessing and predicting acute adverse reactions to Cannabis

Cardiovascular and Respiratory Effects of Cannabis Use by Route of Administration: A Systematic Review

Aim: Knowledge of the cardiovascular and respiratory effects of cannabis use by route of administration is unclear. This evidence is necessary to increase clinical and public health awareness given the recent trend in cannabis legalization, normalization, and surge in the availability and usage of various forms of cannabis products. Methods: Search was conducted in Web of Science, ProQuest, Psych INFO, Scopus, Embase, and Medline databases, and subsequently in the references of retrieved articles. Peer-reviewed articles published between 2009 and 2023, that reported on cardiovascular and respiratory effects of cannabis use by route of administration were included. Studies with no report of the route of administration and combined use of other illicit substances were excluded. The review was guided by Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Results: Of the 1873 articles retrieved, 42 met inclusion criteria encompassing six case reports, 21 reviews, and 15 empirical studies. Four administration routes were identified: smoking, vaping, oral ingestion, and dabbing. Smoking was the most common route of administration and was associated with both respiratory effects, such as bronchitis, dyspnea, and chronic obstructive lung disease, and cardiovascular effects including tachycardia, ventricular arrhythmias, and myocardial infarction. Cannabis edibles were associated with minimal respiratory effects. Tachycardia was the most common cardiovascular effect and was associated with all routes of administration. Conclusion: Cannabis use does cause cardiovascular and respiratory effects, but the conclusion remains tentative of the cardiovascular and respiratory effects by route of administration due to methodological limitations of the studies.

Solitary Cannabis Use and Related Consequences Among College Students During the COVID-19 Pandemic

Solitary cannabis use has been associated with greater cannabis problems than social use and may be increasingly prevalent due to pandemic-related isolation. However, little is known about patterns, correlates, and consequences of solitary cannabis use. This study sought to characterize solitary cannabis use since pandemic onset, examine psychosocial risk factors, and examine interactions between solitary and social cannabis use frequency on cannabis consequences. College students (N = 168) who were lifetime cannabis users at a private, northeastern university in the US completed an online cross-sectional survey in fall of 2020. Past-year solitary cannabis use was common among life-time cannabis users (42% past year, 29% monthly or more), especially among past-year regular cannabis users (85% monthly or more). Solitary use frequency was associated with interpersonal sensitivity and pandemic-related stress. Further, solitary use attenuated associations of social use frequency with cannabis consequences, such that social use frequency was associated with greater consequences only among exclusively social users. In contrast, regardless of social use frequency, solitary users reported greater cannabis consequences than exclusively social users. Findings suggest solitary cannabis use is concurrently associated with greater cannabis consequences, and affective risk factors (interpersonal sensitivity, pandemic stress) should be considered for prevention and intervention strategies.

Predictors of morning cannabis use among young adults: Between- and within-person associations from 24 consecutive months of data

Morning cannabis use is associated with heavier, frequent cannabis use and more cannabis-related negative consequences, yet little empirical research has examined its predictors. Using 24 months of longitudinal data, the present study tested demographic, psychosocial, and behavioral predictors of morning cannabis use among young adults at the monthly- and person-levels. Young adults (N = 778) were part of a larger study on substance use and social role transitions; participants completed a baseline survey and up to 24 consecutive monthly surveys. Hypotheses were tested using logistic multilevel models to estimate odds ratios for any vs. no morning use in a given month. At the monthly level, social anxiety motives and cannabis use frequency on a given month were positively associated with morning cannabis use. At the person level, typical coping motives, average cannabis use frequency, and male sex were positively associated with morning cannabis use. Findings advance our understanding of individual and psychosocial predictors of morning cannabis use among young adults. Notably, social anxiety motives may represent a malleable target for intervention efforts that could reduce risky use patterns associated with morning use. Such efforts may be especially prudent for young men, as our findings indicated morning cannabis use probabilities were much higher for men than women.

Adverse outcomes of cannabis use in Canada, before and after legalisation of non-medical cannabis: cross-sectional analysis of the International Cannabis Policy Study

OBJECTIVES

To date, there is little evidence on the extent to which cannabis legalisation affects the prevalence of adverse events from cannabis at the population level. The current study examined trends in the prevalence of adverse events among people who consumed cannabis before and after Canada's legalisation of recreational cannabis.

DESIGN

Data come from the first four survey waves of the International Cannabis Policy Study, which were conducted online annually immediately prior to non-medical cannabis legalisation in Canada in October 2018, and in the three following years (2019-2021).

PARTICIPANTS

The current analysis included 18 285 Canadian respondents aged 16-65 who reported cannabis use in the past 12 months.

OUTCOME MEASURES

Primary outcomes included types of adverse events experienced from cannabis use, medical help-seeking and the types of products used. Weighted logistic regression models examined differences in help-seeking, emergency room usage and the experience of cannabinoid hyperemesis syndrome across survey years.

RESULTS

Approximately one-third of people who consume cannabis reported experiencing at least one adverse event within the past 12 months, including 5% of consumers who sought medical help for an adverse event, most commonly for panic attacks, feeling faint/dizzy/passing out, heart/blood pressure problems and nausea/vomiting. The prevalence of seeking help and the types of adverse events were similar before (2018) and after legalisation (2019-2021); however, the proportion of consumers seeking help from emergency rooms increased postlegalisation (F=2.77, p=0.041). Adverse events were associated with various product types, with dried flower and oral oils accounting for the largest proportion of events. Help-seeking associated with cannabis edibles significantly decreased after legalisation (p=0.001).

CONCLUSIONS

Substantial proportions of people who consume cannabis report adverse events, suggesting widespread difficulty in 'dosing'. Few changes were observed in the prevalence of adverse events reported by consumers since legalisation; however, the location of medical help-seeking and associated products used have changed postlegalisation.

A Survey Study of Individuals Using Hexahydrocannabinol Cannabis Products: Use Patterns and Perceived Effects

Introduction: Across the cannabis market, multiple cannabinoids have seen rapid growth. Considering the differing effects between specific cannabinoids, it is critical to assess effects on an individual level. Hexahydrocannabinol (HHC) is one intoxicating cannabinoid that became more accessible due to regulatory shifts. The purpose of the current study was to provide descriptive data regarding HHC use patterns and perceived effects within a sample of participants who endorsed recent HHC use. Methods: One hundred nine individuals self-reported use of an HHC-cannabis product at least once within 6 months and completed an HHC use questionnaire via Prolific, an online crowdsourcing platform. Results: Findings suggest recent HHC users are using HHC relatively frequently (∼10 days during the past month) for various indications, including anxiety and pain. HHC was perceived to yield more good than bad effects, including relaxation and euphoria. Approximately 17% of the sample reported adverse effects, and ∼20% of those who stopped using HHC experienced some withdrawal symptoms. Few meaningful sex differences in subjective effect ratings were observed. Discussion: The current study provides critical preliminary data about consumer use patterns and perceived effects related to HHC. Such data are needed to further research on the potential therapeutic as well as detrimental effects of HHC and to better inform the consumers, health professionals, and regulators about a cannabinoid that is widely available the market.

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

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.

An observational study of safety and clinical outcome measures across patient groups in the United Kingdom Medical Cannabis Registry

BACKGROUND

There is a paucity of high-quality data on patient outcomes and safety after initiating treatment with cannabis-based medicinal products (CBMPs). The aim of this study was to assess the clinical outcomes and safety of CBMPs by analyzing patient-reported outcome measures and adverse events across a broad spectrum of chronic conditions.

RESEARCH DESIGN AND METHODS

This study analyzed patients enrolled in the UK Medical Cannabis Registry. Participants completed the EQ-5D-5L to assess health-related quality of life, Generalized Anxiety Disorder-7 (GAD-7) questionnaire to measure anxiety severity, and the Single-item Sleep Quality Scale (SQS) to rate sleep quality at baseline and follow-up after 1, 3, 6, and 12 months.

RESULTS

A total of 2833 participants met inclusion criteria. The EQ-5D-5L index value, GAD-7, and SQS all improved at each follow-up (p < 0.001). There was no difference in EQ-5D-5L index values between former or current illicit cannabis consumers and naïve patients (p > 0.050). Adverse events were reported by 474 (16.73%) participants.

CONCLUSIONS

This study suggests that CBMPs are associated with an improvement in health-related quality of life in UK patients with chronic diseases. Treatment was tolerated well by most participants, but adverse events were more common in female and cannabis-naïve patients.

Endocannabinoid System: Chemical Characteristics and Biological Activity

The endocannabinoid system (eCB) has been studied to identify the molecular structures present in Cannabis sativa. eCB consists of cannabinoid receptors, endogenous ligands, and the associated enzymatic apparatus responsible for maintaining energy homeostasis and cognitive processes. Several physiological effects of cannabinoids are exerted through interactions with various receptors, such as CB1 and CB2 receptors, vanilloid receptors, and the recently discovered G-protein-coupled receptors (GPR55, GPR3, GPR6, GPR12, and GPR19). Anandamide (AEA) and 2-arachidoylglycerol (2-AG), two small lipids derived from arachidonic acid, showed high-affinity binding to both CB1 and CB2 receptors. eCB plays a critical role in chronic pain and mood disorders and has been extensively studied because of its wide therapeutic potential and because it is a promising target for the development of new drugs. Phytocannabinoids and synthetic cannabinoids have shown varied affinities for eCB and are relevant to the treatment of several neurological diseases. This review provides a description of eCB components and discusses how phytocannabinoids and other exogenous compounds may regulate the eCB balance. Furthermore, we show the hypo- or hyperfunctionality of eCB in the body and how eCB is related to chronic pain and mood disorders, even with integrative and complementary health practices (ICHP) harmonizing the eCB.

A First-Tier Framework for Assessing Toxicological Risk from Vaporized Cannabis Concentrates

Vaporization is an increasingly prevalent means to consume cannabis, but there is little guidance for manufacturers or regulators to evaluate additive safety. This paper presents a first-tier framework for regulators and cannabis manufacturers without significant toxicological expertise to conduct risk assessments and prioritize additives in cannabis concentrates for acceptance, elimination, or further evaluation. Cannabinoids and contaminants (e.g., solvents, pesticides, etc.) are excluded from this framework because of the complexity involved in their assessment; theirs would not be a first-tier toxicological assessment. Further, several U.S. state regulators have provided guidance for major cannabinoids and contaminants. Toxicological risk assessment of cannabis concentrate additives, like other types of risk assessment, includes hazard assessment, dose-response, exposure assessment, and risk characterization steps. Scarce consumption data has made exposure assessment of cannabis concentrates difficult and variable. Previously unpublished consumption data collected from over 54,000 smart vaporization devices show that 50th and 95th percentile users consume 5 and 57 mg per day on average, respectively. Based on these and published data, we propose assuming 100 mg per day cannabis concentrate consumption for first-tier risk assessment purposes. Herein, we provide regulators, cannabis manufacturers, and consumers a preliminary methodology to evaluate the health risks of cannabis concentrate additives.

Pilot clinical and pharmacokinetic study of Δ9-Tetrahydrocannabinol (THC)/Cannabidiol (CBD) nanoparticle oro-buccal spray in patients with advanced cancer experiencing uncontrolled pain

This pilot study aimed to assess the safety, tolerability, pharmacokinetics and exploratory analgesic effect of a novel water-soluble oro-buccal nanoparticle spray of a cannabis-based medicine (MDCNS-01) in patients with advanced incurable malignancy with unrelieved pain from opioid analgesic. The study was a non-blinded single arm 2 stage study. Stage I was a single escalating dose (n = 5) [2.5 mg Δ9-THC and 2.5 mg CBD) versus a 3-fold escalated dose. Stage II was an up-titrated dose in patients with advanced cancers and intractable pain (n = 25). During Stage I with an increased cannabis-based medicine dose, maximum observed plasma concentrations of cannabinoids were dose dependant. The water-soluble formulation in the current study resulted in a higher median (min, max) systemic exposure of Δ9-THC than CBD (AUC from 2.5 mg each of Δ9-THC and CBD, was 1.71 ng mL.h-1 (1.1, 6.6) and 0.65 ng mL.h-1 (0.49, 4.1), respectively). During stage II a subgroup of patients diagnosed with breast and prostate cancers with bone metastases, had the highest mean pain score improvement from baseline of 40% (unadjusted) and 33% (adjusted for rescue medication use). For all patients the most reported adverse events were mild or moderate drowsiness affecting 11 (44%) and 4 (6%) patients, respectively, and nausea and vomiting that affected 18 (72%) patients. The water-soluble cannabis-based medicine provided acceptable bioavailability for Δ9-THC/CBD, appeared safe and tolerable in advanced incurable cancers with uncontrolled pain with preliminary evidence of analgesic efficacy.

Rates and correlates of cannabis-associated psychotic symptoms in over 230,000 people who use cannabis

Cannabis, a widely used psychoactive substance, can trigger acute cannabis-associated psychotic symptoms (CAPS) in people who use cannabis (PWUC). To assess rates and correlates of CAPS requiring emergency medical treatment, we analyzed data from an international sample of PWUC (n = 233,475). We found that 0.47% (95%CI 0.42; 0.52) PWUC reported lifetime occurrence of CAPS, defined as the occurrence of hallucinations and/or paranoia requiring emergency medical treatment following the use of cannabis. A range of factors correlated with risk of CAPS in the last year: higher rates were observed in young individuals [risk ratio (RR) 2.66, compared to older PWUC] and those residing in Denmark (RR 3.01, compared to PWUC from other countries). Furthermore, risk was elevated in those using predominantly high-potency resin (RR 2.11, compared to PWUC using herbal cannabis), those mixing cannabis with tobacco (RR 2.15, compared to PWUC not mixing with tobacco) and those with a diagnosis of psychosis (RR 14.01), bipolar (RR 4.30), anxiety (RR 2.92) and depression (RR 2.68), compared to individuals without a mental health diagnosis. Taken together, acute self-limiting psychotic symptoms in the context of cannabis use may occur in about 1 in 200 PWUC's lifetime. Some individuals could be particularly sensitive to the adverse psychological effects of cannabis, such as young individuals or those with pre-existing mental health vulnerabilities. In light of the movements towards legalization of recreational cannabis, more research should focus on the potential harms related to cannabis use, to educate PWUC and the public about risks related to its use.

Self-Reported Effects of Cannabis on ADHD Symptoms, ADHD Medication Side Effects, and ADHD-Related Executive Dysfunction

OBJECTIVE

People with ADHD are more likely to use cannabis but little is known about the effects of cannabis on ADHD symptoms, ADHD medication side effects, or ADHD-related executive dysfunction.

METHOD

Students (n = 1,738) completed an online survey containing measures of ADHD symptoms, cannabis use, perceived effects of cannabis on ADHD symptoms and medication side effects, as well as executive dysfunction.

RESULTS

Participants with ADHD who have used cannabis reported that cannabis has acute beneficial effects on many symptoms of ADHD (e.g., hyperactivity, impulsivity). Further, they perceived cannabis to improve most of their medication side effects (e.g., irritability, anxiety). Finally, cannabis use frequency was a significant moderator of the associations between symptom severity and executive dysfunction.

CONCLUSION

Results suggest people with ADHD may be using cannabis to self-medicate for many of their symptoms and medication side effects and that more frequent use may mitigate ADHD-related executive dysfunction.

Medical Cannabis for Headache Pain: a Primer for Clinicians

PURPOSE OF REVIEW

Public acceptance of Cannabis sativa L. (cannabis) as a therapeutic option grows despite lags in both research and clinician familiarity. Cannabis-whether as a medical, recreational, or illicit substance-is and has been commonly used by patients. With ongoing decriminalization efforts, decreased perception of harms, and increased use of cannabis in the treatment of symptoms and disease, it is critical for clinicians to understand the rationale for specific therapies and their medical and practical implications for patients. In view of the opioid crisis, overall patient dissatisfaction, and lack of adherence to current chronic pain and headache therapies, this review provides up-to-date knowledge on cannabis as a potential treatment option for headache pain.

RECENT FINDINGS

Research into the use of cannabinoids for disease treatment have led to FDA-approved drugs for seizures, nausea, and vomiting caused by cancer chemotherapy; and for decreased appetite and weight loss in people with HIV/AIDS. For a wide variety of conditions and symptoms (including chronic pain), cannabis has gained increasing acceptance in society. The effects of cannabidiol (CBD) and tetrahydrocannabinol (THC) in pain pathways have been significantly elucidated. An increasing number of retrospective studies have shown a decrease in pain scores after administration of cannabinoids, as well as long-term benefits such as reduced opiate use. Yet, there is no FDA-approved cannabis product for headache or other chronic pain disorders. More is being done to determine who is likely to benefit from cannabis as well as to understand the long-term effects and limitations of the treatment. Cannabis can refer to a number of products derived from the plant Cannabis sativa L. Relatively well-tolerated, these products come in different configurations, types, and delivery forms. Specific formulations of the plant have been shown to be an effective treatment modality for chronic pain, including headache. It is important for clinicians to know which product is being discussed as well as the harms, benefits, contraindications, interactions, and unknowns in order to provide the best counsel for patients.

Reasons for cannabidiol use: a cross-sectional study of CBD users, focusing on self-perceived stress, anxiety, and sleep problems

BACKGROUND

Public and medical interest in cannabidiol (CBD) has been rising, and CBD is now available from various sources. Research into the effects of low-dose CBD on outcomes like stress, anxiety, and sleep problems have been scarce, so we conducted an online survey of CBD users to better understand patterns of use, dose, and self-perceived effects of CBD.

METHODS

The sample consisted of 387 current or past-CBD users who answered a 20-question online survey. The survey was sent out to CBD users through email databases and social media. Participants reported basic demographics, CBD use patterns, reasons for use, and effects on anxiety, sleep, and stress.

RESULTS

The sample (N = 387) consisted of 61.2% females, mostly between 25 and 54 years old (72.2%) and primarily based in the UK (77.4%). The top 4 reasons for using CBD were self-perceived anxiety (42.6%), sleep problems (42.5%), stress (37%), and general health and wellbeing (37%). Fifty-four per cent reported using less than 50 mg CBD daily, and 72.6% used CBD sublingually. Adjusted logistic models show females had lower odds than males of using CBD for general health and wellbeing [OR 0.45, 95% CI 0.30-0.72] and post-workout muscle-soreness [OR 0.46, 95%CI 0.24-0.91] but had higher odds of using CBD for self-perceived anxiety [OR 1.60, 95% CI 0.02-2.49] and insomnia [OR 1.87, 95% CI 1.13-3.11]. Older individuals had lower odds of using CBD for general health and wellbeing, stress, post-workout sore muscles, anxiety, skin conditions, focusing, and sleep but had higher odds of using CBD for pain. Respondents reported that CBD use was effective for stress, sleep problems, and anxiety in those who used the drug for those conditions.

CONCLUSION

This survey indicated that CBD users take the drug to manage self-perceived anxiety, stress, sleep, and other symptoms, often in low doses, and these patterns vary by demographic characteristics. Further research is required to understand how low doses, representative of the general user, might impact mental health symptoms like stress, anxiety, and sleep problems.

A content analysis of internet information sources on medical cannabis

BACKGROUND

Medical cannabis users report that their knowledge regarding cannabis is predominantly from their own personal experiences and the Internet.

OBJECTIVE

We summarize and describe information found through Internet searches on medical cannabis in English language websites.

METHODS

We used terms related to medical cannabis in the Google search engine between November and December 2019. Resulting websites were catalogued and coded for content, including mentions of health and medical conditions, pharmacology, dosage, harmful or adverse effects, harm reduction techniques, cautions or warnings, products for sale, and credentials.

RESULTS

We coded 344 web pages on 179 unique websites. Cannabis was mentioned for the treatment of 151 different medical and health conditions, only four of the twenty most frequently mentioned conditions have received substantial empirical support for cannabis or cannabinoid treatment. Information content varied widely across sites, only a small proportion of sites included information on pharmacology, dosage, risks, and other aspects that are requirements for pharmaceutical drugs. Information provided was only moderately related to conclusions in the emerging scientific literature.

CONCLUSIONS

Given the rise in cannabis use within the U.S. and the reliance on the Internet as a source of information, considerable efforts are needed to provide accurate on-line cannabis education to minimize harms and maximize benefits for individuals and society.