Grant: Travel Awards - Institute Community Support

Background. Chronic obstructive pulmonary disease (COPD) is characterized by pathophysiological abnormalities in pulmonary function that contribute to the symptom of breathlessness, which is pervasive in this patient population. It follows, that improving airway function is essential to the symptomatic management of breathlessness in COPD. Available therapies, including inhaled bronchodilators and anti-inflammatory agents, appear to be sub-optimal at improving airway function in advanced COPD. Therefore, it is important to identify novel adjunct therapies that may improve airway function in COPD. A series of studies conducted ~40 years ago demonstrated an acute bronchodilator effect of smoked cannabis in healthy and asthmatic adults that was comparable in magnitude and duration of effect to the short-acting beta2-adrenergic receptor agonist, isoproterenol. On the basis of these observations, the purpose of this randomized, double-blind, placebo controlled, crossover trial was to evaluate the efficacy of inhaled vaporized cannabis in improving pulmonary function (i.e. inducing bronchodilation), breathlessness and exercise intolerance in subjects with severe to very severe COPD and chronic refractory breathlessness. Results and Conclusion. Compared with their respective pre-treatment conditions, neither placebo nor inhaled vaporized cannabis had an effect on pulmonary function, breathlessness and exercise tolerance in subjects with severe to very severe COPD. Additional studies are required to explore the therapeutic potential of cannabis in COPD.