Case studies in cannabis vaporization (2010)

Cannabis remains the world's most popular illicit drug despite its documented contribution to respiratory problems. The vaporizer heats cannabis without igniting it. Previous work suggests that vaporizers have the potential to minimize respiratory irritation, but it has not been used as an intervention yet. We sought to establish the feasibility of the vaporizer as an intervention for cannabis smokers with respiratory problems. Four cannabis users who reported respiratory symptoms (including two tobacco smokers) agreed to stop smoking cannabis and use the vaporizer for 1 month. The vaporizer appeared to be a practical and acceptable method for the administration of cannabis in users with respiratory problems. After 1 month of vaporizer use, self-reported respiratory symptoms improved dramatically. Measures of lung function (forced expiratory volume (FEV1) and forced vital capacity (FVC)) showed more modest improvements. Vaporizing proved reactive for tobacco smokers, leading them to decrease cigarette smoking and confounding interpretations of improvement. Nevertheless, those who smoked cannabis exclusively also benefited from the vaporizer. We attempted a reversal design where participants would then return to smoking but all refused. These results suggest that the cannabis vaporizer is acceptable to users, and has the potential to decrease cannabis-related respiratory problems. The device may increase awareness about respiratory health in cannabis users who also smoke cigarettes. Randomized control trials with large samples of users and longer durations of vaporizing appear warranted. Given the reactive effect of the vaporizer on tobacco use, such trials may have to focus initially on those who smoke cannabis but not tobacco. [Author's abstract]