Acute and chronic effects of marijuana smoking on pulmonary alveolar permeability

Review of Cases of E-Cigarette or Vaping Product Use-Associated Lung Injury (EVALI) and Brief Review of the Literature

Since the appearance of the E-Cigarette in the early 2000s, its industry, popularity, and prevalence have risen dramatically. In the past, E-Cigarette use with the vaping of nicotine or cannabis products had been associated with a few reported cases of lung injury. However, in 2019, thousands of cases of E-Cigarette or vaping product use-associated lung injury (EVALI) were reported in the United States. Evidence linked this outbreak with vaping of tetrahydrocannabinol (THC). We report two confirmed cases of EVALI and their associated clinical, radiologic, and pathologic features. This report supports the growing body of information regarding EVALI. It also discusses various substances, particularly vitamin E acetate, which has been suggested as a causative agent.

A Case Series of Vaping-Associated Lung Injury Requiring Mechanical Ventilation

OBJECTIVES

Vaping-associated lung injury has rapidly become a nationwide epidemic and a threat to public health. In this case series, we describe unique clinical features of severe vaping-associated lung injury, defined as respiratory failure due to vaping that requires mechanical ventilation.

DATA SOURCES

Clinical observation of four patients.

STUDY SELECTION

Case series.

DATA EXTRACTION

Data and images were extract from medical records after approval was obtained from the institutional review board.

DATA SYNTHESIS

Four patients were admitted to the ICU with severe manifestation of vaping-associated lung injury. Although every case required mechanical ventilatory support (venovenous extracorporeal membrane oxygenation in one patient), all patients survived and were discharged without supplemental oxygen. Systemic corticosteroids were administered in three patients and N-acetyl cysteine in one. A postdischarge pulmonary function test in one patient was normal except for mildly decreased diffusing capacity.

CONCLUSIONS

Based on our experience, prognosis of severe vaping-associated lung injury appears favorable with aggressive supportive care, although there is evidence from existing literature that mortality rate might rise with increasing disease severity. Underlying mechanism of lung injury might be similar between vaping-associated lung injury and amiodarone pneumonitis. Foamy or lipid-laden macrophages, seen in both conditions, might be a marker of cytotoxicity from substances contained in e-cigarettes, such as vitamin E acetate. Systemic corticosteroids, and possibly N-acetyl cysteine, could be considered as therapeutic adjuncts in vaping-associated lung injury. Serial pulmonary function tests should be obtained in these patients to monitor for potential long-term complications. The primary limitations of this case series are its small sample and lack of longitudinal follow-up data.

Nicotinic acetylcholine receptor availability in cigarette smokers: effect of heavy caffeine or marijuana use

RATIONALE

Upregulation of α4β2* nicotinic acetylcholine receptors (nAChRs) is one of the most well-established effects of chronic cigarette smoking on the brain. Prior research by our group gave a preliminary indication that cigarette smokers with concomitant use of caffeine or marijuana have altered nAChR availability.

OBJECTIVE

We sought to determine if smokers with heavy caffeine or marijuana use have different levels of α4β2* nAChRs than smokers without these drug usages.

METHODS

One hundred and one positron emission tomography (PET) scans, using the radiotracer 2-FA (a ligand for β2*-containing nAChRs), were obtained from four groups of males: non-smokers without heavy caffeine or marijuana use, smokers without heavy caffeine or marijuana use, smokers with heavy caffeine use (mean four coffee cups per day), and smokers with heavy marijuana use (mean 22 days of use per month). Total distribution volume (Vt/fp) was determined for the brainstem, prefrontal cortex, and thalamus, as a measure of nAChR availability.

RESULTS

A significant between-group effect was found, resulting from the heavy caffeine and marijuana groups having the highest Vt/fp values (especially for the brainstem and prefrontal cortex), followed by smokers without such use, followed by non-smokers. Direct between-group comparisons revealed significant differences for Vt/fp values between the smoker groups with and without heavy caffeine or marijuana use.

CONCLUSIONS

Smokers with heavy caffeine or marijuana use have higher α4β2* nAChR availability than smokers without these drug usages. These findings are likely due to increased nicotine exposure but could also be due to an interaction on a cellular/molecular level.

How Harmonious and Obsessive Passion for Alcohol and Marijuana Relate to Consumption and Negative Consequences

OBJECTIVE

Although the concepts of harmonious and obsessive passion have been productive in explaining why people eagerly engage in such activities as sports, Internet use, and gambling, previous research has not yet extended these models to explain alcohol and marijuana use among college students. The current research was conducted to clarify the relationships among harmonious and obsessive passion, alcohol and marijuana use, and negative consequences.

METHOD

Two studies were conducted using online assessments. In Study 1, 748 heavy drinking college students (58% female) were recruited and completed measures of passion for drinking alcohol, alcohol use, and alcohol-related negative consequences. In Study 2, 352 regular marijuana-using students (54% female) were recruited and completed assessments of marijuana passion, marijuana use, and marijuana-related consequences.

RESULTS

Study 1 found that among heavy drinking college students, harmonious passion was a stronger predictor of increased consumption than was obsessive passion, whereas obsessive passion was a stronger predictor of alcohol-related problems than was harmonious passion. Study 2 revealed similar findings with regard to harmonious passion predicting marijuana consumption; however, unlike Study 1, no significant difference between the passions was found in predicting marijuana-related problems.

CONCLUSIONS

This research provides a novel perspective on motivation for alcohol and marijuana use. Findings suggest that understanding the locus of young adults' passion for substance use may be helpful in identifying those who are likely to develop a substance use disorder and therefore may be the most in need of assistance and intervention.

Acute effects of cigarette smoke on inflammation and oxidative stress: a review

Compared with the effects of chronic smoke exposure on lung function and airway inflammation, there are few data on the acute effects of smoking. A review of the literature identified 123 studies investigating the acute effects of cigarette smoking on inflammation and oxidative stress in human, animal, and in vitro models. An acute smoking model is a relatively easy and sensitive method of investigating the specific effects of cigarette smoke on oxidative stress and inflammation. Acute smoke exposure can result in tissue damage, as suggested by increased products of lipid peroxidation and degradation products of extracellular matrix proteins. Acute cigarette smoke has a suppressive effect on the number of eosinophils and several inflammatory cytokines, possibly due to the anti-inflammatory effect of carbon monoxide. An acute smoking model can supplement other ways of studying the effects of smoking and is an as yet underinvestigated method for intervention studies in smoking related diseases.

Pulmonary effects of illicit drug use

The lungs are at considerable risk from the use of injected or inhaled illicit drugs. The extent and clinical significance of illicit drug induced lung damage is not known completely. Drug use leads to an increase in infectious pulmonary disease, historically in relation to nonsterile injection techniques, and, more recently, in relation to HIV infection and its pulmonary manifestations. Barotrauma related to "smoking topography" or errant injections also represents a real risk of drug use. Although granulomatous disease that involves the pulmonary vasculature and interstitium is probably common in injection drug users, the clinical consequence of such is difficult to estimate. What effect smoked or injected illicit drugs have on short- and long-term pulmonary function also is hard to ascertain. The ubiquitous use of tobacco among users of illicit drugs certainly has confounding effects. Given that illicit drug use is common and that the "popular" drugs of abuse change from generation to generation, the pulmonary physician must remain informed about, and alert for, the effects of drugs of abuse.

Marijuana use among adolescents

More than half of US adolescents will experiment with marijuana. Of those who try marijuana more than once, approximately one third will subsequently use marijuana regularly, although most will have stopped by their late 20s. Although genetic predisposition plays the most important role in determining who will develop dependence, environmental factors influence who will initiate marijuana use. One of the challenges for prevention and treatment programs is that the immediate adverse effects of marijuana use are not extreme, and many adolescents have difficulty in making decisions based on future risks. Therefore, the consequences of leaving school early, having unprotected sex, and driving while intoxicated are often insufficient to deter adolescents from using marijuana. Thus, it is not surprising that current prevention and treatment programs have had limited success in decreasing the rates of initiation and regular use of marijuana among adolescents. However, the accumulation of data about marijuana use in adolescents has the potential to enable the development of more effective prevention and treatment programs.

Marijuana. Respiratory tract effects

Daily marijuana smoking has been clearly shown to have adverse effects on pulmonary function and produce respiratory symptomatology (cough, wheeze, and sputum production) similar to that of tobacco smokers. Based on the tobacco experience, decrements in pulmonary function may be predictive of the future development of chronic obstructive pulmonary disease (COPD). However, in the absence of alpha-1-antitrypsin deficiency, the habitual marijuana-only smoker would likely have to smoke 4-5 joints per day for a span of at least 30 yr in order to develop overt manifestations of COPD. The mutagenic/carcinogenic properties of marijuana smoke are also well-established. The potential for induction of laryngeal, oropharyngeal, and possibly bronchogenic carcinoma from marijuana has been documented by several case reports and observational series. Despite this, a relative risk ratio for the development of these tumors has not yet been quantified. Based on a higher frequency of case reports for upper airway cancer compared to bronchogenic carcinoma, marijuana smoking may have a more deleterious effect on the upper respiratory tract. However, this hypothesis remains speculative at best, pending confirmation by longitudinal studies.

Effects of 'crack' cocaine on pulmonary alveolar permeability

BACKGROUND

Lung clearance of 99mTc-labeled diethylenetriamine pentaacetate (DTPA) is a sensitive test of altered alveolar epithelial permeability that has been found to be increased in smokers of tobacco, as well as a small number of healthy smokers of crack cocaine, suggesting the possibility of subclinical crack-related lung injury.

STUDY OBJECTIVE

To evaluate further whether habitual smoking of cocaine alone alters alveolar permeability, whether crack smoking adds to or potentiates the effects of tobacco and/or marijuana, and whether experimental cocaine smoking acutely alters DTPA lung clearance.

DESIGN

Observational cohort study (habitual cocaine smoking) and single-blind crossover study (experimental cocaine administration).

SUBJECTS

Fourteen habitual smokers of cocaine alone (CS), 19 smokers of cocaine and tobacco (CTS), 3 smokers of cocaine and marijuana, 12 smokers of cocaine, tobacco, and marijuana (CMTS), and 5 smokers of marijuana plus tobacco (MTS). Results obtained in the crack-smoking subjects were compared with data previously obtained in 10 nonsmokers (NS), 9 smokers of tobacco alone (TS), 10 smokers of marijuana alone (MS), and 4 additional MTS.

METHODS

Subjects underwent measurements of DTPA radioaerosol lung clearance after refraining from marijuana and/or cocaine for > 12 h and from tobacco for >2 h. Ten of the 48 crack users were tested on two days 1 to 2 weeks apart within 2 h of experimental smoking of three physiologically active or inactive doses (total 98.8+/-15.5 or 8.5+/-2.5 mg, respectively) of cocaine base. Lung clearance half-times (T1/2) were computed from time-activity curves for each lung.

RESULTS

T1/2 values for each lung in CS and MS were comparable to those of NS, while TS, MTS, CTS, and CMTS had significantly shorter clearance rates than NS (p<0.01; three-way analysis of variance). No additive or interactive effects on T1/2 were noted among tobacco, cocaine, and/or marijuana. No acute effect of experimental cocaine smoking on T1/2 was noted.

CONCLUSION

Whereas regular smoking of tobacco alone or with other substances increases alveolar epithelial permeability, habitual smoking of cocaine and/or marijuana has no measurable effect on alveolar permeability in the absence of tobacco nor any additive effect to that of tobacco alone.

Marijuana Use: Current Issues and New Research Directions

Due to recent evidence of the increasing frequency of marijuana use among adolescents and young adults, and due to the many remaining research issues regarding this drug, it is appropriate to summarize some of the important data about marijuana and to suggest some directions for research and service. This article first provides a review of the history, botany, active ingredients, effects, and negative consequences of marijuana use. Next, prevention and cessation of marijuana use are discussed. Finally, this paper provides a selective examination of current issues in marijuana research. Several salient issues are highlighted including its preference among certain subgroups (high risk youth and ethnic differences), its relations with illegal behavior (marijuana use and driving, current marijuana-related legislation, and marijuana use and violence), and its recent portrayal in the media.