By Dr Farsalinos
A new study by our group was published today in the journal Scientific Reports. The study evaluated nicotine absorption from e-cigarette use, comparing a group of experienced vapers (daily users of e-cigarettes for an average period of 19 months) with na´ve users (all of whom were smokers). We used equipment that was considered advanced at the time of performing the study (late 2013 ľ an Evic battery device with an EVOD clearomizer, at 9W). Participants were asked to take 10 puffs within 5 minute and then use the e-cigarette ad lib for 60 minutes. Blood samples were collected at baseline, 5min, 20 min, 35min, 50min and 65min and plasma nicotine levels were measured. Additionally, we recorded puff number and puff duration in order to explore the association between puff topography and plasma nicotine levels.
The main finding of the study was that na´ve users had significantly lower plasma nicotine levels compared to experienced users. That was associated with shorter puff duration. The association was statistically significant but weak, indicating that other factors are important in nicotine delivery to the bloodstream besides puff duration (such as inhalation time, depth of inhalation). Of note, the puff number was equal in the two groups, thus it had no effect on the differences in observed plasma nicotine levels. Both groups had lower plasma nicotine levels at 5min compared to smoking 1 tobacco cigarette.
The conclusion was that, obviously, there is no risk of nicotine overdose from intended use of e-cigarettes in first-time users. Na´ve users obtain less nicotine from e-cigarettes compared to experienced vapers, verifying that there is learning curve in e-cigarette use. Smokers should be properly informed that they might not get enough nicotine during e-cigarette initiation and that they need to adjust their use patterns. This is important in order to avoid an initial disappointment of smokers related to low nicotine absorption, which might result in abandoning e-cigarette use and eventually in an unsuccessful attempt to quit smoking.
As mentioned above, the equipment used in this study is now considered outdated, and we have evidence that new-generation atomizers deliver more nicotine to the aerosol (especially when using high power levels). We expect that new-generation systems will deliver nicotine at a faster rate and thus be more acceptable for smokers by satisfying their nicotine need.