A Systematic Review of the Respiratory Effects of Inhalational Marijuana

This systematic review focuses on respiratory effects of inhalational marijuana. The systematic review of the literature was conducted using a comparative method between 2 researchers. Abstracts were reviewed for inclusion of respiratory effects related to inhalational marijuana. Relevant abstracts were collected, and full text articles were retrieved for review. Articles were removed if they did not contain burning marijuana; were animal studies; or were editorials, systematic reviews, commentaries, non-English language, or non-respiratory-related articles. Forty-eight articles were collected and categorized by respiratory effects. In particular, lung cancer, bullous emphysema/COPD, and other respiratory symptoms were the primary categories. Articles were noted by study population country, sample size, age distribution, and findings that were pertinent to respiratory health. The research indicates that there is a risk of lung cancer from inhalational marijuana as well as an association between inhalational marijuana and spontaneous pneumothorax, bullous emphysema, or COPD. A variety of symptoms have been reported by inhalational marijuana smokers, including wheezing, shortness of breath, altered pulmonary function tests, cough, phlegm production, bronchodilation, and other symptoms. It is important to stay current with research findings to educate patients on this smoking behavior.