Toxicant Formation in Dabbing: The Terpene Story

Mechanistic Rationale for Ketene Formation during Dabbing and Vaping

Ketene is one of the most toxic vaping emissions identified to date. However, its high reactivity renders it relatively challenging to identify. In addition, certain theoretical studies have shown that realistic vaping temperature settings may betoo low to produce ketene. Each of these issues is addressed herein. First, an isotopically labeled acetate precursor is used for the identification of ketene with enhanced rigor in vaped aerosols. Second, discrepancies between theoretical and experimental findings are explained by accounting for the effects of aerobic (experimental) versus anaerobic (simulated and theoretical) pyrolysis conditions. This finding is also relevant to explaining the relatively low-temperature production of aerosol toxicants beyond ketene. Moreover, the study presented herein shows that ketene formation during vaping is not limited to molecules possessing a phenyl acetate substructure. This means that ketene emission during vaping, including from popular flavorants such as ethyl acetate, may be more prevalent than is currently known.

Cannabis vaporisation: Understanding products, devices and risks

ISSUES

Vaporisation is a common method of cannabis administration. Inconsistent terminology and jargon regarding vaporisation has led to confusion. The increasing public interest and access to cannabis, combined with possible safety concerns associated with certain cannabis vaping products, warrants improved consumer and public and health care professional knowledge.

APPROACH

To improve this knowledge, we conducted a review of the common terminology, regulatory status, products and device types related to cannabis vaporisation.

KEY FINDINGS

Cannabis vaporisation devices can be separated into nine types. While vaporisation reduces respiratory risks associated with cannabis combustion, not all vaping products and device types carry the same level of safety. Metered dose inhalers and dried product vaporisers present the lowest safety risk due to a lower risk of toxin exposure and the use of lower tetrahydrocannabinol potency products.

IMPLICATIONS

As both vaping and cannabis use increase in popularity, focusing on accurate health education will help facilitate health promotion to encourage lower risk use. The current lack of understanding on risk differences between types of cannabis vaporisation is a missed opportunity for harm reduction. Increased opportunities for public health and health care professional education on different cannabis vaporisation devices and associated risks are warranted. Improvements to health warning labelling may also be beneficial.

CONCLUSION

Not all cannabis vaporisation devices and products carry the same level of risk. A better understanding of risk differentiation is needed among consumers and health professionals. Continued research, policy development and health education can lead to safer cannabis vaporisation.

Thermal reaction products and formation pathways of two monoterpenes under in situ thermal desorption conditions that mimic vaping coil temperatures

Vaping has become more popular and different brands and types of vaping devices have rapidly emerged. However, little is known about the potential health risks of human inhalation exposures to the volatile chemicals in the vapour, which includes both directly vaporised components of vaping liquid and their reaction products formed during vaping processes. This study investigated reaction products of two monoterpenes (α-pinene and terpinolene) that are used as flavouring agents in vaping liquids with a focus on the identification of reaction products and their formation pathways. The thermal desorption was conducted under an in situ condition that is in the range of heating coil temperature in vaping by thermally desorbing the chemicals at a temperature range of 100-300 °C. Additional clean air was introduced during the thermal desorption. 36 and 29 reaction products were identified from α-pinene and terpinolene, respectively, at a relative concentration of 0.01% and greater in the desorbed mixture. 3-Carene was the dominant reaction product of α-pinene, while reaction products of terpinolene was dominated by p-isopropenyltoluene. Several reaction pathways including ring opening, allylic oxidation, cyclo-etherification, Wagner-Meerwein rearrangement, epoxidation, cleavage and removal of partial structure, and dehydration were involved in the formation of various reaction products. These pathways and resulting relative concentrations of residual parent compound and reaction products were influenced by both temperature and amount of air present during thermal desorption. The study results demonstrate possible existence of reaction products from thermally labile chemicals like monoterpenes in vaping aerosols and can help inform policies regulating vaping devices and products to protect public health.

Volatile Markers for Cancer in Exhaled Breath-Could They Be the Signature of the Gut Microbiota?

It has been shown that the gut microbiota plays a central role in human health and disease. A wide range of volatile metabolites present in exhaled breath have been linked with gut microbiota and proposed as a non-invasive marker for monitoring pathological conditions. The aim of this study was to examine the possible correlation between volatile organic compounds (VOCs) in exhaled breath and the fecal microbiome by multivariate statistical analysis in gastric cancer patients (n = 16) and healthy controls (n = 33). Shotgun metagenomic sequencing was used to characterize the fecal microbiota. Breath-VOC profiles in the same participants were identified by an untargeted gas chromatography-mass spectrometry (GC-MS) technique. A multivariate statistical approach involving a canonical correlation analysis (CCA) and sparse principal component analysis identified the significant relationship between the breath VOCs and fecal microbiota. This relation was found to differ between gastric cancer patients and healthy controls. In 16 cancer cases, 14 distinct metabolites identified from the breath belonging to hydrocarbons, alcohols, aromatics, ketones, ethers, and organosulfur compounds were highly correlated with 33 fecal bacterial taxa (correlation of 0.891, p-value 0.045), whereas in 33 healthy controls, 7 volatile metabolites belonging to alcohols, aldehydes, esters, phenols, and benzamide derivatives correlated with 17 bacterial taxa (correlation of 0.871, p-value 0.0007). This study suggested that the correlation between fecal microbiota and breath VOCs was effective in identifying exhaled volatile metabolites and the functional effects of microbiome, thus helping to understand cancer-related changes and improving the survival and life expectancy in gastric cancer patients.

Is Recreational Marijuana Use Associated With Changes in the Vital Signs or Anesthetic Requirements During Intravenous Sedation?

PURPOSE

The prevalence of tetrahydrocannabinol (THC) use is increasing in the general population due to its increased availability, legality, and cultural acceptability. The purpose of the current study was to measure the association of THC use on the vital signs and anesthetic requirements during intravenous (IV) sedation procedures in recreational marijuana users.

METHODS

A retrospective cohort study was performed. A study sample was chosen from July 2018 to May 2022 based on the following inclusion criteria: patients who underwent toxicology screening due to their history of recent drug use and received IV sedation. The predictor variable of the present study is THC status grouped into THC+ and THC-. THC status was established using urine toxicology. Patients who screened positive for THC were coded THC+. Patients who screened negative for THC were coded THC-. Primary outcome variable was changes in vital signs, including mean arterial pressure (MAP), heart rate (HR), and respiratory rate (RR) during IV sedation procedures in THC+ and THC- groups. Secondary outcome variable was difference in medication (midazolam, fentanyl, propofol, and ketamine) requirements in THC+ and THC- groups. Covariates included age, gender, race, weight, duration of surgery, smoking history, and alcohol use, data on psychiatric diagnosis and psychiatric medications. Descriptive statistics and 2-sample t test were calculated. Statistical significance was set at P < .05.

RESULTS

In total, 53 patients met the inclusion criteria and were included in the study, with 27 patients in the THC+ group and 26 patients in the THC- group. There were no significant statistical differences in the MAP_%, HR_%, and RR_% at T₅, T₁₀, T₂₀, and T₃₀ between the THC+ and THC- groups. When comparing THC+ and THC- groups, in bivariate analyses, the THC+ group required, on average, higher doses of fentanyl [83.82 mcg compared to 65 mcg (P = .02)] and propofol [70 mg compared to 45.26 mg (P = .03)] during IV sedation. However, after adjusting the effect of age, gender, and weight, THC had no significant effect on midazolam (P-value = .28), fentanyl (P-value = .12), propofol (P-value = .06) and ketamine (P-value = .86) requirements.

CONCLUSIONS

These findings suggest there are no differences in vital signs or anesthetic requirements between the THC+ and THC- groups.

Vaping Cannabinoid Acetates Leads to Ketene Formation

Δ⁸-THC acetate is a relatively new psychoactive cannabis product that is available online and in vape shops across the United States since it is currently largely unregulated. Because it contains a similar substructure to vitamin E acetate, which has been shown to form the poison gas ketene during vaping, we investigated potential ketene formation from Δ⁸-THC acetate, as well as two other cannabinoids acetates, CBN acetate and CBD acetate, under vaping conditions. Ketene was consistently observed in vaped condensates from all three cannabinoid acetates as well as from a commercial Δ⁸-THC acetate product purchased online.

Vaping Aerosols from Vitamin E Acetate and Tetrahydrocannabinol Oil: Chemistry and Composition

The popularity of vaping cannabis products has increased sharply in recent years. In 2019, a sudden onset of electronic cigarette/vaping-associated lung injury (EVALI) was reported, leading to thousands of cases of lung illness and dozens of deaths due to the vaping of tetrahydrocannabinol (THC)-containing e-liquids that were obtained on the black market. A potential cause of EVALI has been hypothesized due to the illicit use of vitamin E acetate (VEA) in cannabis vape cartridges. However, the chemistry that modifies VEA and THC oil, to potentially produce toxic byproducts, is not well understood under different scenarios of use. In this work, we quantified carbonyls, organic acids, cannabinoids, and terpenes in the vaping aerosol of pure VEA, purified THC oil, and an equal volume mixture of VEA and THC oil at various coil temperatures (100-300 °C). It was found under the conditions of our study that degradation of VEA and cannabinoids, including Δ⁹-THC and cannabigerol (CBG), occurred via radical oxidation and direct thermal decomposition pathways. Evidence of terpene degradation was also observed. The bond cleavage of aliphatic side chains in both VEA and cannabinoids formed a variety of smaller carbonyls. Oxidation at the ring positions of cannabinoids formed various functionalized products. We show that THC oil has a stronger tendency to aerosolize and degrade compared to VEA at a given temperature. The addition of VEA to the e-liquid nonlinearly suppressed the formation of vape aerosol compared to THC oil. At the same time, toxic carbonyls including formaldehyde, 4-methylpentanal, glyoxal, or diacetyl and its isomers were highly enhanced in VEA e-liquid when normalized to particle mass.

Thermography of cannabis extract vaporization cartridge heating coils in temperature- and voltage-controlled systems during a simulated human puff

Vaporized cannabis is believed to be safer than smoking, but when heated to excessive temperatures nearing combustion (>900 °C) harmful byproducts may form. While some cannabis extract vaporizers operate well below these high temperatures, heating coil temperatures obtained during actual use are frequently not reported and many operate at high temperatures. We report on two major objectives: 1) development of an infrared thermography method to measure heating coil temperatures in cannabis extract vaporizers during a simulated puff and 2) a comparison of temperature- to voltage- controlled cannabis extract vaporization systems during a puff. Infrared thermography was used to measure heating coil temperatures in one temperature-controlled and two voltage-controlled systems. The cartridges were modified for direct line-of-sight on the heating coils, the wick and coils were saturated with cannabis extract, and fixtures were developed to force two liters per minute air flow past the coils for the full duration of the puff allowed by the device. The voltage-controlled systems produced higher temperatures with greater variability than the temperature-controlled system. At the highest temperature setting (420 °C) the temperature-controlled system reached an average heating coil temperature of 420 ± 9.5 °C whereas the 4.0V setting on the variable voltage system reached an average temperature of 543 ± 95.9 °C and the single voltage (3.2V) system an average of 450 ± 60.8 °C. The average temperature at the lowest setting (270 °C) on the temperature-controlled system was 246 ± 5.1 °C and the variable voltage system (2.4V) was 443 ± 56.1 °C. Voltage alone was a poor indicator of coil temperature and only the temperature-controlled system consistently maintained temperatures less than 400 °C for the full puff duration. These lower temperatures could reduce the likelihood of harmful thermal degradation products and thus may reduce potential health risk to consumers when vaporizing cannabis extracts.

Identification of a New Family of Prenylated Volatile Sulfur Compounds in Cannabis Revealed by Comprehensive Two-Dimensional Gas Chromatography

Cannabis sativa L. produces over 200 known secondary metabolites that contribute to its distinctive aroma. Studies on compounds traditionally associated with the scent of this plant have focused on those within the terpenoid class. These isoprene-derived compounds are ubiquitous in nature and are the major source of many plant odors. Nonetheless, there is little evidence that they provide the characteristic "skunk-like" aroma of cannabis. To uncover the chemical origins of this scent, we measured the aromatic properties of cannabis flowers and concentrated extracts using comprehensive two-dimensional gas chromatography equipped with time-of-flight mass spectrometry, flame ionization detection, and sulfur chemiluminescence. We discovered a new family of volatile sulfur compounds (VSCs) containing the prenyl (3-methylbut-2-en-1-yl) functional group that is responsible for this scent. In particular, the compound 3-methyl-2-butene-1-thiol was identified as the primary odorant. We then conducted an indoor greenhouse experiment to monitor the evolution of these compounds during the plant's lifecycle and throughout the curing process. We found that the concentrations of these compounds increase substantially during the last weeks of the flowering stage, reach a maximum during curing, and then drop after just one week of storage. These results shed light on the chemical origins of the characteristic aroma of cannabis and how volatile sulfur compound production evolves during plant growth. Furthermore, the chemical similarity between this new family of VSCs and those found in garlic (allium sativum) suggests an opportunity to also investigate their potential health benefits.

Cannabis Vaping: Existing and Emerging Modalities, Chemistry, and Pulmonary Toxicology

The outbreak of e-cigarette or vaping product use-associated lung injury (EVALI) has been cause for concern to the medical community, particularly given that this novel illness has coincided with the COVID-19 pandemic, another cause of severe pulmonary illness. Though cannabis e-cigarettes tainted with vitamin E acetate were primarily associated with EVALI, acute lung injuries stemming from cannabis inhalation were reported in the literature prior to 2019, and it has been suggested that cannabis components or additives other than vitamin E acetate may be responsible. Despite these concerning issues, novel cannabis vaporizer ingredients continue to arise, such as Δ8-tetrahydrocannabinol, Δ10-tetrahydrocannabinol, hexahydrocannabinol, and cannabichromene. In order to address cannabis e-cigarette safety and vaping in an effective manner, we provide a comprehensive knowledge of the latest products, delivery modes, and ingredients. This perspective highlights the types of cannabis vaping modalities common to the United States cannabis market, with special attention to cartridge-type cannabis e-cigarette toxicology and their involvement in the EVALI outbreak, in particular, acute lung injurious responses. Novel ingredient chemistry, origins, and legal statuses are reviewed, as well as the toxicology of known cannabis e-cigarette aerosol components.

Analgesic Potential of Terpenes Derived from Cannabis sativa

Pain prevalence among adults in the United States has increased 25% over the past two decades, resulting in high health-care costs and impacts to patient quality of life. In the last 30 years, our understanding of pain circuits and (intra)cellular mechanisms has grown exponentially, but this understanding has not yet resulted in improved therapies. Options for pain management are limited. Many analgesics have poor efficacy and are accompanied by severe side effects such as addiction, resulting in a devastating opioid abuse and overdose epidemic. These problems have encouraged scientists to identify novel molecular targets and develop alternative pain therapeutics. Increasing preclinical and clinical evidence suggests that cannabis has several beneficial pharmacological activities, including pain relief. Cannabis sativa contains more than 500 chemical compounds, with two principle phytocannabinoids, Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD). Beyond phytocannabinoids, more than 150 terpenes have been identified in different cannabis chemovars. Although the predominant cannabinoids, Δ9-THC and CBD, are thought to be the primary medicinal compounds, terpenes including the monoterpenes β-myrcene, α-pinene, limonene, and linalool, as well as the sesquiterpenes β-caryophyllene and α-humulene may contribute to many pharmacological properties of cannabis, including anti-inflammatory and antinociceptive effects. The aim of this review is to summarize our current knowledge about terpene compounds in cannabis and to analyze the available scientific evidence for a role of cannabis-derived terpenes in modern pain management. SIGNIFICANCE STATEMENT: Decades of research have improved our knowledge of cannabis polypharmacy and contributing phytochemicals, including terpenes. Reform of the legal status for cannabis possession and increased availability (medicinal and recreational) have resulted in cannabis use to combat the increasing prevalence of pain and may help to address the opioid crisis. Better understanding of the pharmacological effects of cannabis and its active components, including terpenes, may assist in identifying new therapeutic approaches and optimizing the use of cannabis and/or terpenes as analgesic agents.

Advancing the science on cannabis concentrates and behavioural health

ISSUES

The Cannabis sativa L. plant contains hundreds of phytocannabinoids, but putatively of highest importance to public health risk is the psychoactive cannabinoid delta-9-tetrahydrocannabinol (THC), which is associated with risk for cannabis use disorder, affective disturbance, cognitive harm and psychomotor impairment. Recently, there has been an increase in the use and availability of concentrated cannabis products (or 'concentrates') that are made by extracting cannabinoids from the plant to form a product with THC concentrations as high as 90-95%. These products are increasingly popular nationwide. The literature on these widely available high potency concentrates is limited and there are many unknowns about their potential harms.

APPROACH

This review covers the state of the research on cannabis concentrates and behavioural health-related outcomes and makes recommendations for advancing the science with studies focused on accurately testing the risks in relation to critical public and behavioural health questions.

KEY FINDINGS

Data point to unique behavioural health implications of concentrate use. However, causal, controlled and representative research on the effects of cannabis concentrates is currently limited.

IMPLICATIONS

Future research is needed to explore chronic, acute and developmental effects of concentrates, as well as effects on pulmonary function. We also highlight the need to explore these relationships in diverse populations.

CONCLUSION

While the literature hints at the potential for these highly potent products to increase cannabis-related behavioural health harms, it is important to carefully design studies that more comprehensively evaluate the impact of concentrates on THC exposure and short- and long-term effects across user groups.

Dabbing-Induced Hypersensitivity Pneumonitis

Dabbing has been gaining popularity among young people in recent years due to its ability to deliver a high concentration of tetrahydrocannabinol. When produced illegally, it is usually contaminated by toxic substances and associated with multiple health hazards. We present the case of a 66-year-old woman who developed hypersensitivity pneumonitis after dabbing butane hash oil for the first time and was successfully treated with corticosteroids with complete resolution of her symptoms. This case report emphasizes the respiratory complications associated with using a noxious substance like butane hash oil and gives physicians an insight into the diagnosis and management of dabbing-induced hypersensitivity pneumonitis.

Strategies for Nonpolar Aerosol Collection and Heavy Metals Analysis of Inhaled Cannabis Products

The rapid growth of inhalable cannabis concentrates raises questions about the safety of acute and chronic exposure to these aerosol mixtures. Due to the nonpolar nature of the aerosol mixture created from cannabis vapor cartridges, traditional aqueous-based capture methods used in e-cigarette or tobacco cigarette studies for analysis of metals are insufficient. Moreover, hydrophobic cannabis concentrates are not miscible with dilute aqueous acids and therefore not ideal for metal spiking unlike electronic nicotine delivery systems. This study describes a method of spiking nonaqueous matrices with aqueous metals standards to investigate aerosolization and recovery of the metals. It also compares various methods for nonpolar aerosol capture and subsequent analysis of 10 metals (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, and Sn) in two model cannabis matrices, flower and concentrate. Spiked cannabis concentrates were vaped in commercially available cartridges, and their aerosol mixtures were investigated for recovery of heavy metals via ICP-MS. Spiked flower samples were also combusted to compare collection rates of the 10 metals. Results show that not all metals that are present in the concentrate or flower can be fully recovered in the aerosol capture processes at standard voltage settings or combustion temperatures. These studies also demonstrate the importance of a nonpolar solvent as part of the aerosol collection to increase the recovery of some metals. The high concentration of some metals seen in the concentrate suggests that the devices themselves are potential routes of exposure. The ICP-MS analysis method was further validated by evaluating different parameters including linearity, matrix effect, limit of detection, limit of quantitation, and repeatability.

Air monitoring for illegal drugs including new psychoactive substances: A review of trends, techniques and thermal degradation products

The detection of illicit psychotropic substances in both indoor and outdoor air is a challenging analytical discipline, and the data from such investigation may provide intelligence in a variety of fields. Applications of drug monitoring in air include providing data on national and international drug consumption trends, as monitored by organisations such as the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) and the United Nations Office on Drugs and Crime (UNODC). Air monitoring enables mapping of illicit drug manufacturing, dealing or consumption in cities and the identification of emergent compounds including the recent proliferation of new psychoactive substances (NPS). The rapid spread of NPS has changed the global drug market with greater diversity and dynamic spread of such compounds over several nations. This review provides an up to date analysis of key thematic areas within this analytical discipline. The process of how illicit psychotropic substances spread from emission sources to the atmosphere is considered alongside the sampling and analytical procedures involved. Applications of the technique applied globally are reviewed with studies ranging from the analysis of individual dwellings through to major international air-monitoring campaigns providing evidence on global drug trends. Finally, we consider thermal breakdown products of illicit psychotropic substances including NPS that are released upon heating, combustion or vaping and related potential for exposure to these compounds in the air.

Emissions from Heated Terpenoids Present in Vaporizable Cannabis Concentrates

Vaporizable cannabis concentrates (VCCs) consumed as a liquid (vaping) or a waxy solid (dabbing) are becoming increasingly popular. However, their associated emissions and impacts have not been fully described. Mixtures containing different proportions of 12 VCC terpenoids and high MW compounds were heated at 100-500 °C inside a room-sized chamber to simulate emissions. Terpenoids, thermal degradation byproducts, and ultrafine particles (UFPs) were quantified in the chamber air. Air samples contained over 50% of emitted monoterpenes and less than 40% of released sesquiterpenes and terpene alcohols. Eleven degradation byproducts were quantified, including acrolein (1.3-3.9 μg m^-3) and methacrolein (2.0 μg m^-3). A large amount of UFPs were released upon heating and remained airborne for at least 3 h. The mode diameter increased from 80 nm at 100 °C to 140 nm at 500 °C, and particles smaller than 250 nm contributed to 90% of PM_1.0. The presence of 0.5% of lignin, flavonoid, and triterpene additives in the heated mixtures resulted in a threefold increase in the particle formation rate and PM_1.0 concentration, suggesting that these high-molecular-weight compounds enhanced aerosol inception and growth. Predicted UFP emission rates in typical consumption scenarios (6 × 10¹¹-2 × 10¹³ # min^-1) were higher than, or comparable with, other common indoor sources such as smoking and cooking.

The influence of terpenes on the release of volatile organic compounds and active ingredients to cannabis vaping aerosols

Cannabinoid and VOC emissions from vaping cannabis concentrates vary depending on terpene content, power level and consumption method.

Vaping and e-cigarette use. Mysterious lung manifestations and an epidemic

Electronic (e)-cigarette use and the practice of vaping has rapidly expanded both in adult smokers and previously nicotine naïve youths. Research has focused on harm reduction in adults using e-cigarettes to stop or reduce traditional cigarette use, but the short and long-term safety of these products has not been established. Vaping has more recently been associated with a growing list of pulmonary complications with the most urgent being the e-cigarette or vaping product use-associated lung injury (EVALI) epidemic. This review details the inhalant toxicology of vaping products, the described lung diseases associated with vaping with a focus on EVALI, and the predicted long-term consequences of e-cigarette use, including increased asthma severity.

Alleviative effects of Cannabis flower on migraine and headache

OBJECTIVE

Few studies to date have measured the real-time effects of consumption of common and commercially available Cannabis products for the treatment of headache and migraine under naturalistic conditions. This study examines, for the first time, the effectiveness of using dried Cannabis flower, the most widely used type of Cannabis product in the United States, in actual time for treatment of headache- and migraine-related pain and the associations between different product characteristics and changes in symptom intensity following Cannabis use.

METHODS

Between 06/10/2016 and 02/12/2019, 699 people used the Releaf Application to record real-time details of their Cannabis use, including product characteristics and symptom intensity levels prior to and following self-administration; data included 1910 session-level attempts to treat headache- (1328 sessions) or migraine-related pain (582 sessions). Changes in headache- or migraine-related pain intensity were measured on a 0-10 scale prior to, and immediately, following Cannabis consumption.

RESULTS

Ninety-four percent of users experienced symptom relief within a two-hour observation window. The average symptom intensity reduction was 3.3 points on a 0-10 scale (standard deviation = 2.28, Cohen's d = 1.58), with males experiencing greater relief than females (P < 0.001) and a trend that younger users (< 35 years) experience greater relief than older users (P = 0.08). Mixed effects regression models showed that, among the known (i.e., labeled) product characteristics, tetrahydrocannabinol levels 10% and higher are the strongest independent predictors of symptom relief, and this effect is particularly prominent in headache rather than migraine sufferers (P < 0.05), females (P < 0.05) and younger users (P < 0.001). Females and younger users also appear to gain greater symptom relief from flower labeled as "C. indica" rather than "C. sativa" or other hybrid strains.

CONCLUSION

These results suggest that whole dried Cannabis flower may be an effective medication for treatment of migraine- and headache-related pain, but the effectiveness differs according to characteristics of the Cannabis plant, the combustion methods, and the age and gender of the patient.

A review of toxic effects of electronic cigarettes/vaping in adolescents and young adults

In this review, we examine the known and suspected toxicity of electronic cigarettes (e-cigarettes) in adolescents and young adults, to improve awareness of risks and identification of complications of their use. The use of e-cigarettes, or "vaping," is exploding among the pediatric population. E-cigarettes heat a solution containing a psychoactive compound, most commonly nicotine or tetrahydrocannabinol (THC), along with flavorings and other additives to a vapor, which users inhale. Since their introduction in the early 2000s, e-cigarette use is now prolific among youth, per the Monitoring the Future survey, with over 40% of high school seniors reporting use within the past year. Adolescents are vulnerable to the risks of e-cigarettes, as they are targeted as new consumers with advertisements and flavoring compounds, and are not utilizing them as a means to smoking cessation. The pulmonary risks of vaping are rapidly emerging, with the most immediately alarming being the condition electronic-cigarette/vaping associated lung injury (EVALI). Additionally, there have been more recent studies showing extrapulmonary effects including cardiovascular, immunologic and neuro-developmental effects. Many of these effects are likely dose-dependent. Public health efforts are urgently needed to decrease or eliminate new e-cigarette initiation, and support should be established to assist current e-cigarette users with cessation. We strongly advocate for the elimination of e-cigarette flavorings and advertising directed at adolescents, and call for physicians to be cognizant of this expanding epidemic.

Method Validation Approaches for Analysis of Constituents in ENDS

OBJECTIVE

We assessed how many peer-reviewed publications reporting chemical quantities and/or yields from electronic nicotine delivery systems (ENDS) have included adequate method validation characteristics in the publication for appropriate interpretation of data quality for informing tobacco regulatory science.

METHODS

We searched 5 databases (Web of Knowledge, PubMed, SciFinder, Embase, EBSCOhost) for ENDS publications between January 2007 and September 2018. Of the 283 publications screened, 173 publications were relevant for analysis. We identified the publications that report a certain degree of control in data quality, ie, the publications that report marginally validated methods (MVMs). MVMs refer to the methods that: (1) report 3 or more International Conference on Harmonisation (ICH) method validation characteristics, (2) state the method was validated, (3) cite their own previous publication(s) that report MVMs, or (4) use a method within the accreditation scope of an accredited laboratory.

RESULTS

Overall, 97 publications (56%) report MVMs in their studies. This percentage also reflects the publication distribution for the majority of the 28 chemicals measured by MVMs.

CONCLUSIONS

This study highlights the need for reporting sufficient validation characteristics following appropriate guidance to ensure the accuracy and reliability of the published analytical data for proper data interpretations that may support policy.

Pine rosin identified as a toxic cannabis extract adulterant

Pine rosin (colophony) has been identified as a potentially new adulterant in cannabis oil. Its inhalation toxicity poses a significant health concern to users. For example, pine rosin fumes are released during soldering, and have been cited as a causative agent of occupational asthma. Symptoms also include desquamation of bronchial epithelium, which has also been observed in e-cigarette or vaping product used-associated lung injury (EVALI) patients. The sample analyzed herein was acquired from a cannabis industry source, also contains medium chain triglycerides and oleamide, the latter of which is a hypnotic that is commonly found in the synthetic marijuana product Spice, or K2. A combination of proton nuclear magnetic resonance (¹H NMR) and high pressure liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESIMS) was used to unambiguously identify major pine rosin ingredients such as abietic and other resin acids. Comparison to commercial samples of pure pine rosin confirmed the assignment.

Lung Injury Associated with E-Cigarette or Vaping Product Use

In the United States, an epidemic of unusual and severe lung disease associated with the use of e-cigarettes, or vaping, began in spring 2019. By fall 2019, the US Centers for Disease Control and Prevention had received reports of e-cigarette or vaping product use-associated lung injury (EVALI) cases from all state health departments in the continental US, Hawaii, and the US Virgin Islands. According to the cases, a number of young people had developed severe lung disease characterized by marked shortness of breath and cough. Constitutional and gastrointestinal symptoms are common. Clinical laboratory test results in EVALI are often consistent with nonspecific findings of pulmonary/systemic inflammation. Many reported cases of EVALI have required critical care interventions including noninvasive positive airway pressure, cardiotonic pressors, and intubation/mechanical ventilation. The need for extracorporeal membrane oxygenation support has been reported in some cases. The lung disease is diffuse and has multiple pathologies. Patients are often treated with intravenous or oral corticosteroids with clinical improvement, although the natural history of the disease remains unknown. In rare cases, the outcome is fatal. This article reviews the epidemiology, clinical presentation, radiographic appearance, diagnostic approach, and treatment regimens for patients with vaping-induced lung disease as noted in multiple patients and the current literature. [Pediatr Ann. 2020;49(2):e93-e98.].

Myrcene and terpene regulation of TRPV1

Nociceptive Transient Receptor Potential channels such as TRPV1 are targets for treating pain. Both antagonism and agonism of TRP channels can promote analgesia, through inactivation and chronic desensitization. Since plant-derived mixtures of cannabinoids and the Cannabis component myrcene have been suggested as pain therapeutics, we screened terpenes found in Cannabis for activity at TRPV1. We used inducible expression of TRPV1 to examine TRPV1-dependency of terpene-induced calcium flux responses. Terpenes contribute differentially to calcium fluxes via TRPV1 induced by Cannabis-mimetic cannabinoid/terpenoid mixtures. Myrcene dominates the TRPV1-mediated calcium responses seen with terpenoid mixtures. Myrcene-induced calcium influx is inhibited by the TRPV1 inhibitor capsazepine and Myrcene elicits TRPV1 currents in the whole-cell patch-clamp configuration. TRPV1 currents are highly sensitive to internal calcium. When Myrcene currents are evoked, they are distinct from capsaicin responses on the basis of Imax and their lack of shift to a pore-dilated state. Myrcene pre-application and residency at TRPV1 appears to negatively impact subsequent responses to TRPV1 ligands such as Cannabidiol, indicating allosteric modulation and possible competition by Myrcene. Molecular docking studies suggest a non-covalent interaction site for Myrcene in TRPV1 and identifies key residues that form partially overlapping Myrcene and Cannabidiol binding sites. We identify several non-Cannabis plant-derived sources of Myrcene and other compounds targeting nociceptive TRPs using a data mining approach focused on analgesics suggested by non-Western Traditional Medical Systems. These data establish TRPV1 as a target of Myrcene and suggest the therapeutic potential of analgesic formulations containing Myrcene.

Beyond the Bud: Emerging Methods of Cannabis Consumption for Youth

Cannabis continues to be the most widely used illicit substance among youth, as many teens view the risks of cannabis consumption to be low. With cannabis laws becoming lax and dispensaries becoming more prevalent throughout the United States, highly concentrated Δ-9-tetrahydrocannibinol (THC) is becoming readily available. This article examines the available literature on consumption of concentrated THC, focusing on potential consequences of concentrate use among youth. Various methods for consuming concentrated THC, including ingestion of edibles, vaping, and dabbing, are discussed, along with associated risks of each consumption method. Recommendations for health professionals are provided.

Modeling drug exposure in rodents using e-cigarettes and other electronic nicotine delivery systems

Smoking tobacco products is the leading cause of preventable death worldwide. Coordinated efforts have successfully reduced tobacco cigarette smoking in the United States; however, electronic cigarettes (e-cigarette) and other electronic nicotine delivery systems (ENDS) recently have replaced traditional cigarettes for many users. While the clinical risks associated with long-term ENDS use remain unclear, advancements in preclinical rodent models will enhance our understanding of their overall health effects. This review examines the peripheral and central effects of ENDS-mediated exposure to nicotine and other drugs of abuse in rodents and evaluates current techniques for implementing ENDS in preclinical research.

Aerosol Gas-Phase Components from Cannabis E-Cigarettes and Dabbing: Mechanistic Insight and Quantitative Risk Analysis

Consumption of cannabis by nontraditional methods has surged since the advent of legalization in North America and worldwide. Inhaling cannabis extracts using vaporizers and via dabbing has risen in popularity, while concerns over product safety have not hindered their proliferation. The work herein is the first step toward assessing the safety of vaporizing and dabbing concentrated cannabis extracts as a function of gas-phase reaction products. The gas-phase thermal degradants of Δ⁹-tetrahydrocannabinol (THC) have not been previously investigated. It was found that users may be exposed to concerning degradants such as methacrolein, benzene, and methyl vinyl ketone when using cartridge vaporizers and dabbing. It was shown that THC alone and mixed with terpenes generated similar degradation products and, most notably, elevated levels of isoprene. Importantly, it was shown that added terpenes led to higher levels of gas-phase products compared to THC alone. To estimate cancer and noncancer risks associated with exposure to these and other degradants, quantitative risk assessment was applied to experimentally determined values for dabbing and vaping and literature-sourced levels of hazardous components in cannabis smoke. Overall, gas-phase aerosol products had significantly lower values in dabbing and vaporizing compared to cannabis smoking, although these results should be interpreted in light of potential variations in degradant levels due to disparate usage patterns and the dangers of the higher aerosol concentration of THC.

Frequently asked questions about dabbing concentrates in online cannabis community discussion forums

BACKGROUND

"Dabbing" involves vaporizing a "dab" of cannabis concentrate on a heated "nail," passing the vapour through a water-pipe rig or portable pen device, and inhaling the vapour. While some cannabis industry media claims that this process is cleaner, safer, and more effective for getting high, medical and public health sources raise concerns about residual solvents and pesticides, unexpectedly intense effects, and rapid increases in tolerance. The aim of this study is to characterize the content of questions about dabbing posed in cannabis and dabbing-specific forums on the Reddit social media platform, as well as comment responses to these questions.

METHODS

We conducted a content analysis of one year (2017) of information-seeking user-generated posts to three Reddit online cannabis community discussion forums ("subreddits") that contained the terms "dab" and "question." We also examined post engagement and the types and sentiment of information exchanged in the comment responses.

RESULTS

Across 193 dabbing question posts, the most frequently asked question content was about types and logistical use of devices and related equipment (38%) and comparisons of cannabis products (32%), followed by questions about the step-by-step process of getting high (18%), legal issues (17%), and health concerns (13%). Nearly every post had a response (98%), with a median 5 comments per post and few negative (i.e. hostile, condescending, or trolling) comments (4%). Source of advice or information was stated in about a quarter (26%) of comment responses, with the overwhelming majority of this information (89%) coming from disclosures of personal experience vs. web or commercial sources.

CONCLUSION

People seeking advice online about dabbing inquired most often about logistics of use, but less often about health, tolerance, and legal risks. These findings may be used to inform public health efforts and health practitioner education as cannabis becomes increasingly legal and accessible.

Terpenes in Cannabis sativa - From plant genome to humans

Cannabis sativa (cannabis) produces a resin that is valued for its psychoactive and medicinal properties. Despite being the foundation of a multi-billion dollar global industry, scientific knowledge and research on cannabis is lagging behind compared to other high-value crops. This is largely due to legal restrictions that have prevented many researchers from studying cannabis, its products, and their effects in humans. Cannabis resin contains hundreds of different terpene and cannabinoid metabolites. Many of these metabolites have not been conclusively identified. Our understanding of the genomic and biosynthetic systems of these metabolites in cannabis, and the factors that affect their variability, is rudimentary. As a consequence, there is concern about lack of consistency with regard to the terpene and cannabinoid composition of different cannabis 'strains'. Likewise, claims of some of the medicinal properties attributed to cannabis metabolites would benefit from thorough scientific validation.

A review of the anesthetic implications of marijuana use

Marijuana, derived from plants of the genus Cannabis, is the most commonly used illicit drug in the United States. Marijuana is illegal at the federal level and remains a Drug Enforcement Agency Schedule 1 substance. Nevertheless, most states have passed less stringent legislation related to its use, ranging from decriminalization of possession to allowing medical or even recreational use, and some county and municipal law enforcement agencies have refrained from prosecuting personal possession and/or use even when statute would require such action. Therefore, as use of marijuana becomes more common in the larger population, more patients who are chronic and/or heavy users of marijuana present for surgical procedures, raising the question of best practices to care for these patients in the perioperative period. This review summarizes the known physiologic effects of marijuana in humans, discusses potential implications of marijuana use that the anesthesiologist should consider at each phase of the perioperative period, and outlines recommendations for future study.

Lung injury from inhaling butane hash oil mimics pneumonia

Introduction

“Dabbing”, a relatively new form of THC use which utilizes Butane Hash Oil (BHO), an extraction of dried cannabis containing high levels of butane and terpene byproducts. The extraction process yields a waxy substance that is heated, vaporized and inhaled. We describe a lung injury as a result of BHO use.

Case

A previously healthy 18-year-old female presented to the ED with shortness of breath for 3–4 days. Initial oxygen saturation was 79% on room air. She was refractory to bronchodilators, steroids and supplemental O₂. She has a 1-pack year smoking history and daily BHO abuse. Chest x-ray was positive for bilateral patchy infiltrates with mild hyperinflation. CT was negative for Pulmonary Embolus or other acute pathologic process. Sputum gram stain and blood cultures were negative. Arterial blood gases confirmed a pO2 of 73 mmHg. On physical exam she was tachycardic and tachypneic. Respiratory auscultation showed decreased air entry bilaterally with diffuse expiratory wheezing, bilateral rhonchi and a prolonged expiratory phase. We concluded her severe pneumonitis was secondary to daily BHO inhalation.

Discussion

Heating BHO to high temperatures, releases up to 75% of THC, compared to 5–20% THC in traditional smoked cannabis. At 978°F terpenes degrade into methacrolein and benzene. Methacrolein is structurally similar to acrolein, a pulmonary irritant, which causes acute lung injury and pulmonary edema in laboratory animals. We hypothesize a mechanism of lung injury and acute respiratory failure secondary to inhalation of high levels of methacrolein and benzene related to relatively novel phenomena of BHO use.

Terpene- and terpenoid-based polymeric resins for stereolithography 3D printing

Thiol–ene ‘click’ reactions between terpenes and a four-arm thiol were utilized to produced thermoset 3D printed structures using vat photopolymerisation.

Regulating Cannabis Manufacturing: Applying Public Health Best Practices from Tobacco Control

State legalization and regulation of cannabis, despite continued federal illegality, is a massive shift in regulatory approach. Manufactured cannabis, including concentrates, extracts, edibles, tinctures, topicals and other products, has received less attention than more commonly used dried flower, but represents emerging regulatory challenges due to additives, potency, consumption methods, and abuse and misuse potential. In November 2017, the California Department of Public Health (CDPH) released initial cannabis manufacturing regulations as part of a new state regulatory structure. As the largest U.S. medical cannabis market (and largest legal adult use market in the world beginning in 2018), California's regulatory approach will potentially influence national and global policy. Comparing CDPH's initial regulations to tobacco control best practices reveals that, while the regulations recognize the need to protect public health, prioritizing public health over business interests requires stronger approaches to labeling, packaging, and product formulations. Based on tobacco best practices, we recommend that cannabis regulations incorporate large and proportionately sized informational labels, a prominent universal cannabis symbol, rotating and pictorial health warnings, mandatory plain packaging, a comprehensive ban on characterizing flavors and addictive additives, and strict limits on the potency of inhalable products and those easily confused with non-cannabis products.