[Cannabis use and impairment of respiratory function]

Effects of cannabis smoking on the respiratory system: A state-of-the-art review

The diminished perception of the health risks associated with the consumption of cannabis (marijuana) lead to a progressive increase in its inhalational use in many countries. Cannabis can be smoked through the use of joints, spliffs and blunts, and it can be vaporised with the use of hookah or e-cigarettes. Delta-9 tetrahydrocannabinol (THC) is the main psychoactive component of cannabis smoke but contains numerous other substances. While the recreational use of cannabis smoking has been legalised in several countries, its health consequences have been underestimated and undervalued. The purpose of this review is to critically review the impact of cannabis smoke on the respiratory system. Cannabis smoke irritates the bronchial tree and is strongly associated with symptoms of chronic bronchitis, with histological signs of airway inflammation and remodelling. Altered fungicidal and antibacterial activity of alveolar macrophages, with greater susceptibility to respiratory infections, is also reported. The association with invasive pulmonary aspergillosis in immunocompromised subjects is particularly concerning. Although cannabis has been shown to produce a rapid bronchodilator effect, its chronic use is associated with poor control of asthma by numerous studies. Cannabis smoking also represents a risk factor for the development of bullous lung disease, spontaneous pneumothorax and hypersensitivity pneumonitis. On the other hand, no association with the development of chronic obstructive pulmonary disease was found. Finally, a growing number of studies report an independent association of cannabis smoking with the development of lung cancer. In conclusion, unequivocal evidence established that cannabis smoking is harmful to the respiratory system. Cannabis smoking has a wide range of negative effects on respiratory symptoms in both healthy subjects and patients with chronic lung disease. Given that the most common and cheapest way of assumption of cannabis is by smoking, healthcare providers should be prepared to provide counselling on cannabis smoking cessation and inform the public and decision-makers.

Comparative study of pulmonary functions test among different substances abusers

BACKGROUND

Substance use is a problem that affects people all over the world and is prevalent in different age groups. The lungs in particular, with their unique exposure to the environment and the bloodstream, are vulnerable to damage from substance use and can affect lung function. Efforts have generally focused on cigarettes, while there is little research on different substances of use. The study aimed to detect changes in pulmonary function tests in different substance users.

METHODS

An analytical cross-sectional study was carried out among different substance users at the Abdalaal Elidridi Psychiatric Hospital. A total of 60 adults were included: 16 cannabis users, 16 heroin users, 16 methamphetamine users, and 12 alcohol users. Participants used only one substance. Height and weight were measured, and BMI was calculated. For each participant, pulmonary function tests (PFTs) including forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC ratio and peak expiratory flow rate (PEFR) were measured using an electronic spirometer, and the results were compared with normal reference values for Sudanese subjects matched for age, sex, and height.

RESULTS

A high prevalence of lung function abnormalities (100.0%) is seen in all abusers. Obstructive lung disease is found in 80.0% of patients, and restrictive lung disease is found in 20.0% of cases. The measured FEV1/FVC ratio in different substance groups was lower than the expected normal values of (88.2 ± 2.9%). The mean FEV1/FVC ratio of alcohol was (83.6 ± 7.6%), for heroin, it was (77.3 ± 15.8%), for methamphetamine, it was (77.7 ± 17.8%) and for cannabis, it was (71.03 ± 11.3%), the latter was significantly lower than the other two groups (P < 0.001). Duration of substance use was inversely correlated with the FEV1/FVC ratio (r = -0.378, P 0.001), indicating that a longer duration of substance use correlates with lower FEV1/FVC ratios.

CONCLUSIONS

Obstructive lung abnormalities are frequent in substance abusers. All types of substances have a major deleterious effect on PFTs and harm the respiratory system. More action should be taken to address the effects of substances on the lungs. Awareness, early detection, and intervention are essential.

[Inhaled marijuana and the lung, a toxic cocktail?]

Unlike the well-documented effects of tobacco smoke on the lung, the effects of cannabis smoke remain controversial, the main bias consisting in co-consumption of tobacco. That said, the composition of joint smoke is close to that of cigarettes, containing many compounds that are carcinogenic and/or alter the respiratory epithelium. Confirmed respiratory effects in chronic cannabis smokers include aggravated chronic bronchitis symptoms, a cumulative effect with tobacco on COPD and emphysema occurrence, an increased risk of bullous emphysema, and pneumothorax with heightened risk of recurrence after pleural symphysis. Recent prospective studies have shown a negative impact on lung function, with not only damage to the airways, but also DLCO alteration and an accelerated drop in FEV1. Finally, cannabis smoking is very common among young patients with lung cancer. Its consumption could lead to a different lung cancer profile, potentially more undifferentiated and less accessible to targeted therapy. Questioning about cannabis consumption must be systematic and targeted medical care should be offered.

Atteintes pulmonaires liées au cannabis inhalé

La relation entre cannabis et pathologies pulmonaires est difficile à établir : le cannabis est souvent fumé-mélangé à du tabac (« joint ») et les fumeurs de cannabis fument souvent aussi des cigarettes de tabac.

L’usage régulier de cannabis est un facteur de risque de bronchite chronique.

Il n’y a pas d’association significative entre inhalation de fumée de cannabis et obstruction bronchique, typique de la BPCO.

L’usage de cannabis peut augmenter le risque de sifflements thoraciques et/ou de développement d’un asthme.

L’usage régulier de cannabis est un facteur de risque de pneumopathies infectieuses, avec un risque plus élevé chez les sujets immunodéprimés et notamment les patients infectés par le VIH.

Les résultats des études épidémiologiques sur le risque de cancer bronchique chez les fumeurs de cannabis sont discordants.

Des cas de pneumothorax, pneumomédiastin, pneumopéricarde et pneumorachis ont été décrits chez les fumeurs de cannabis.

Les études épidémiologiques ne montrent pas d’association entre usage de cannabis et emphysème pulmonaire.

Les cannabinoïdes de synthèse, plus récemment introduits sur le marché, ont une toxicité importante. Ils peuvent provoquer des pneumopathies sévères et/ou une dépression respiratoire sévère.

[Asthma and cannabis, cocaine or heroin use]

INTRODUCTION

The use of cannabis, cocaine or heroin can be responsible for many respiratory complications including asthma.

OBJECTIVES

The aim of this systematic literature review of data was to expose the relations between cannabis, cocaine or heroin use and asthma.

RESULTS

Cannabis, cocaine or heroin use by inhalation may be responsible for respiratory symptoms (cough, wheezing), asthma onset, acute asthma exacerbations (which may require intubation and invasive ventilation) or deaths related to asthma. Lower adherence to asthma treatment is also observed. Cannabis induces a rapid bronchodilator effect. In contrast, its chronic use may induce a decrease in specific airway conductance. Studies on forced expiratory volume in one second (FEV1) reduction or decline are discordant.

CONCLUSION

Cannabis, cocaine or heroin use must be considered in cases of acute respiratory symptoms or asthma exacerbation in young persons and practitioners must help illicit substance users to stop their consumption.

[Cannabis: Similarities and differences with tobacco]

Nicotine is the specific psychoactive substance of tobacco while tetrahydrocannabinol (THC) is the specific component of cannabis. The inhalation technique of cannabis is different from that of tobacco smoking: the volume of puffs is larger, inhalation is deeper, and pulmonary retention time is longer. Cannabis addiction is difficult to evaluate, both products often being smoked concomitantly. The principle physical side effects of cannabis affect organs and functions in a similar way to tobacco: pulmonary, cardiovascular, endocrine and stomatological. Gastrointestinal complications such as cannabinoid hyperemesis are specific to cannabis. Some psychological effects of THC may be acute (altered time and space perception, sensory disability, decreased vigilance, mood and dissociative disorders, hallucinations and delirium, impaired learning and memory, impaired cognitive and motor performance, panic attacks and anxiety) or chronic (lack of motivation, disorganisation of thoughts, increase in frequency and severity of schizophrenic crises). Cannabis can also be implicated in traffic and workplace accidents. Synthetic cannabinoids have increased psychotropic and somatic effects due to a greater affinity for brain cannabinoid receptors.

[Acute eosinophilic pneumonia and illicit psychoactive substance use]

Illicit psychoactive substance (IPAS) use can lead to a number of respiratory complications, including acute eosinophilic pneumonia (AEP). Systematic literature review of data on AEP in IPAS users (cannabis, cocaine, heroin and amphetamine). Of two cases of cannabis and tobacco users reported to have developed AEP, one, a teenage15 year old boy presented with acute respiratory distress syndrome (ARSD) which necessitated extracorporeal membrane oxygenation (ECMO). Five cases of AEP in cocaine smokers (crack) are reported, one of which was fatal. The patient presented with acute pulmonary edema and ARDS which progressed to ventricular fibrillation and asystole. A 24-year-old woman presented with AEP after repeated inhalation of heroin. Finally, a case of an amphetamine abuser who developed AEP and ARDS after amphetamine inhalation is reported. The time between the first IPAS use and admission in cases reported ranged from 7 days to 4 years, while time between the last IPAS use and admission was short (less than 15 days). IPAS use must be sought in case of AEP, especially in young adults, and practitioners must advise and help users to stop their consumption.

[Spontaneous pneumothorax and lung emphysema in cannabis users]

INTRODUCTION

If pulmonary complications of tobacco smoking are well documented, those associated with cannabis use are less known.

OBJECTIVES

Systematic literature review of data on pneumothorax and lung emphysema in cannabis users.

DOCUMENTARY SOURCES

Medline, on the period 1980-2018 with the following keywords cannabis or marijuana and pneumothorax or emphysema, limits "title/abstract". Among 97 articles, 42 abstracts have given use to a dual reading to select 20 studies.

RESULTS

Eighteen case reports (8 with SP) showed bullae in the upper lobes in combined cannabis and tobacco smokers (CS) and in the 2 cannabis only smokers (COS). The risk of SP was increased in CS, but not in COS. In patients less than 35-years old presenting with SP, the incidence of bullae on thoracic computed tomography (CT) was higher in CS than in tobacco only smokers (TOS). CT in patients with SP showed no significant difference as regards of the prevalence, location and type of emphysema between CS and TOS. Proportion of low lung density areas was higher in CS than in non-smokers (NS), but was similar in TOS and NS.

CONCLUSION

These results suggest a cumulative toxic effect of tobacco and cannabis on the risk of SP and lung emphysema.

[The respiratory effects of smoking]

A marked increase in the morbidity and mortality of a large number of broncho-pulmonary diseases has been documented in relation to smoking. The influence of tobacco smoking on various respiratory conditions. is discussed: incidence, severity or natural history modification of some respiratory illnesses: obstructive lung diseases (COPD, asthma), lung cancer, bacterial, viral respiratory infections, with the impact of smoking on tuberculosis. Finally, the relationship of tobacco with diffuse interstitial lung disease: protective role of smoking (controversial in sarcoidosis, real in hypersensitivity pneumonitis). The benefits of smoking cessation are described.

[Cannabis and lung. What we know and everything we don't know yet]

Cannabis use increased sharply from 2010 to 2014 in France. Cannabis is often consumed with tobacco, although the use of marijuana is developing. Tobacco and cannabis smoke have many common characteristics in terms of irritants, carcinogens and carbon monoxide. They also differentiate by their dependence mechanisms, with nicotine and its receptors for tobacco and tetra-hydro-cannabinol (THC) and its specific receptors for cannabis. Chronic inhalation (700,000 daily users in France) over a long period most likely increases the relative risk of bronchial cancer. But long-term cohort studies targeting this group of strong cannabis users, especially over time, are lacking. Inhalation of cannabis smoke, despite an acute bronchodilator effect, is associated with the risk of chronic bronchitis in the case of regular use. However, the risk of developing COPD in the exclusive marijuana smoker group with no associated tobacco is not yet clear, with studies yielding discordant results. There is also a lack of long-term follow-up studies of respiratory investigations in large cannabis users. Finally, cannabis smoke contains various cannabinoids, for example cannabidiol which also have anti-inflammatory and antifibrotic properties, with the unconfirmed hypothesis that these properties can partially modulate the deleterious action of cannabis smoke.

[Alveolar haemorrhage following a cannabis water pipe]

Respiratory toxicity of cannabis is well-known today particularly with the new consumption patterns. We report the case of a 25-year-old man admitted for haemoptysis, with unfavourable outcome and acute respiratory failure. Various explorations concluded to acute respiratory distress syndrome secondary to diffuse alveolar haemorrhage. Etiological assessment was initially negative. Outcome was favourable during hospitalization, authorizing the discharge of our patient. Two days later, alveolar haemorrhage recur, with positive toxicological tests for cannabis and the patient admits smoking cannabis by plastic "bang". We illustrate, through this case, the severity of respiratory complications caused by new methods of using cannabis, particularly with plastic 'bang', hence the need to insist of the importance of supported withdrawal and to inform young people how these techniques are serious.ssss.

[Cannabis "bong": A frequent, original and dangerous way of consumption]

The bong is a water pipe craft, used to smoke tobacco or cannabis. The benefit of consuming cannabis as a "bang" is based on the intensity and speed of the effect. The cannabis intoxication can then be associated with disorders of sensory functions, the type of distortion of perceptions or hallucinations, often accompanied by intense anxiety. Bong cannabis consumption appears to be responsible for specific side effects (especially hemoptysis), possibly related to the importance of inhalation of products of combustion of cannabis and combustion of plastic parts used in its manufacture.

[Smoking cessation in smokers with chronic obstructive pulmonary disease]

One out of two smokers who smoke throughout their lifetime will die from a disease related to smoking. Tobacco smoking therefore represents a major global public health issue. Smoking is the leading cause of chronic obstructive pulmonary disease (COPD). Projections for 2020 indicate that by then, COPD will have become the third cause of death and the fifth cause of disability worldwide. Stopping smoking reduces the risk of developing COPD and is an essential treatment for this inflammatory disease. Smoking cessation decreases the prevalence of respiratory symptoms, number of hospitalizations, and decline in FEV1, as well as exacerbation frequency and overall mortality. Among the patients, 38-77% with COPD are smokers. Their daily cigarette consumption and level of nicotine dependence are often high. The combination of high intensity behavioral interventions and medication treatments (nicotine replacement therapy, varenicline, bupropion) is the most effective strategy for smokers with COPD. In contrast, behavioral interventions without medication are not more effective than simple advice to stop. Two factors seem to predict the success of the attempt to quit in smokers with COPD: a strong motivation to quit and the use of smoking cessation medications.

[Cannabis smoking and lung cancer]

Cannabis is the most commonly smoked illicit substance in the world. It can be smoked alone in plant form (marijuana) but it is mainly smoked mixed with tobacco. The combined smoking of cannabis and tobacco is a common-place phenomenon in our society. However, its use is responsible for severe pulmonary consequences. The specific impact of smoking cannabis is difficult to assess precisely and to distinguish from the effect of tobacco. Marijuana smoke contains polycyclic aromatic hydrocarbons and carcinogens at higher concentration than tobacco smoke. Cellular, tissue, animal and human studies, and also epidemiological studies, show that marijuana smoke is a risk factor for lung cancer. Cannabis exposure doubles the risk of developing lung cancer. This should encourage clinicians to identify cannabis use and to offer patients support in quitting.