A pilot study of nicotine delivery to smokers from a metered-dose inhaler

The present study generated preliminary data on the acceptability and pharmacokinetics of nicotine administered by a simple metered-dose inhaler (MDI). We conducted a nonrandomized, open-label cross-over trial of 10 current smokers. On Day 1, a single cigarette was smoked ad libitum. On Day 2, participants took 10 puffs (20 inhalations) of 50 mu g nicotine/puff through the inhaler, and on Day 3, they took 10 puffs (20 inhalations) of 100 mu g nicotine/puff, each over 5 min. Nicotine pharmacokinetics, changes in heart rate and blood pressure, and the acceptability of the inhalers were measured and recorded. Nicotine administered by an MDI produced a median maximum plasma concentration that was about 50% of that obtained by smoking a cigarette (12.5 vs. 25.9 ng/ml) and took twice the time to reach that concentration, 6 versus 3 min. Self-rated satisfaction and reduced urge to smoke were similar for the MDIs and a cigarette. The results suggest that nicotine can be delivered effectively by the pulmonary route using a standard MDI. The inhaler appears to provide a satisfaction level and reduction in the urge to smoke relatively similar to that provided by smoking a cigarette. These conclusions require verification in a larger controlled study.