Pulmonary effects of marijuana inhalation

Abstract

Marijuana is the most commonly used illicit drug around the world. It is most often consumed through smoking, placing the respiratory system in direct contact with the toxic constituents of the drug, which are similar to those of tobacco cigarettes. However, accurate study of the adverse effects of marijuana is difficult to perform, owing to marijuana's illegal status, variation in smoking technique, often short duration of use compared with tobacco and the frequently confounding factor of concomitant consumption of both marijuana and tobacco. Despite this, there is evidence to suggest that marijuana can impair lung function, damage large airway mucosa and possibly contribute to bullous disease, while its carcinogenic potential is controversial.

Marijuana: Current Concepts†

“…Identifying adverse effects of cannabis is challenging because studying an illicit drug can be problematic as can separating out cannabis effects from other drugs that are often taken simultaneously, such as tobacco or alcohol; also, there is variation in techniques of cannabis consumption (90, 92–94). …”

“…Cannabis can lead to increased airway resistance and large airway inflammation though causal links to COPD or macroscopic emphysema remain controversial and unproven (93, 94, 119, 122). Smoking both tobacco and marijuana increases risks for abnormal tracheobronchial histopathology and COPD (122).…”

“…Marijuana smoke contains toxic chemicals in amounts similar to or higher than that found in tobacco and is linked as a potential respiratory tract carcinogen (27, 94, 97, 121). Chronic inflammatory and precancerous airway changes in a dose-dependent relationship as well as increase in airway cancer are reported in cannabis users (91).…”

Pleuritic chest pain and fluid levels on imaging in a heavy cannabis smoker

“…However, it is thought that there may be some link between the manoeuvre used in cannabis smoking, namely a larger inspiratory effort and longer breath holding, and the pattern of pulmonary disease seen in this population 3. Additionally, there is a significant lack of longitudinal data on cannabis smoking and its effects on health 5 6. Furthermore, cannabis smokers also commonly smoke tobacco, and the combination of tobacco and cannabis smoke is also thought to be harmful 2…”

Vanishing Lung Syndrome in a Patient With HIV Infection and Heavy Marijuana Use

“…In subjects who smoke marijuana, the pathological changes of emphysema occur at a younger age (approximately 20 years earlier) than in tobacco smokers [3,4]. These changes can also be distinguished from tobacco induced emphysema by the location of the large pulmonary bullae, found mostly in a paraseptal distribution with a marked predisposition for the upper lobes, as compared to the more uniformly distributed bullae of centrilobular emphysema which are the typical changes associated with a lifetime of tobacco smoking [7,10,11].…”