TL neuro

July 18, 2015

Prevalence of E-cigarette use in 8th-12th graders

Filed under: E-cigarettes, Tobacco/Nicotine, Vape inhalation — mtaffe @ 5:47 pm

The Monitoring the Future survey added electronic cigarettes to its survey for the first time in 2014. The summary tables and figures and full monographs are available for the clicking.

Results show show that 17.1% of high school seniors reported using an E-cigarette at least once in the past 30 days. Rates were almost as high for 10th grade students (16.2%) and somewhat lower for 8th graders (8.7%).

To put this in perspective the 30 day prevalence for cigarettes was 13.6% for 12th graders, 7.2% for 10th and 4.0% for 8th graders. So twice as many 8th and 10th grade students have at least tried an E-cigarette as have tried a regular cigarette.

6.8% of 12th grade students report smoking one or more cigarettes per day. The rate for 10th graders is only 3.3% and 1.4% for 8th graders. One way to put together the E-cigarette/cigarette ratios from the three grade ranges is to observe that daily smoking is more likely with older students. These individuals may either have less need to resort to E-cigarettes for availability reasons or they may reflect the fact that E-cigarettes may not produce good nicotine levels until smokers are motivated to learn to use them.

For those that are unfamiliar with drug use rates in these grade levels, E-cigarette use is high. The percentage of respondents who used any illicit drug other than marijuana in the past 30 days was 7.7%, 5.6% and 3.3% for 12th, 10th and 8th graders respectively. Marijuana rates were 21.2%, 16.6% and 6.5%. The 30 day rates for 12th graders for individual drugs of interest are much lower: 1.0% cocaine or LSD, 1.4% Ecstasy, 0.4% heroin or PCP, 6.4% for any prescription drug.

Since this was only added to the MtF survey recently, we cannot make much from a single point estimate of E-cigarette use. Maybe this was the peak of a new fad, maybe the beginning of a sustained trend.

What we do know is that substantial numbers of adolescents are sampling the use of these devices.


June 30, 2015

Smokers have to adapt to e-cigarettes to maximize nicotine yield

Filed under: Cannabis, Public Health, Tobacco/Nicotine — mtaffe @ 1:20 pm

One of the reasons that smoked/inhaled drug delivery is highly associated with addiction is that this route allows humans to exquisitely titrate their dosing. Thus for drugs like nicotine that become aversive at higher doses, smoking tobacco in several punctate inhalations over a short interval of time permits the user to avoid unpleasant dose levels.

This contrasts, for example, with buccal administration. If anyone recalls sampling chewing tobacco as a youth, you will understand what I mean. The relatively slowed onset and the larger available dose of the wad of tobacco or snuff packed up against the gums is frequently associated with severe nausea in the naive user.

A similar situation obtains with cannabis for which smoking has been the preferred route of administration. There is, however, relatively familiar use of cannabis via the oral route- think pot brownies. Increasingly, the medical marijuana entities are also selling a variety of edibles for oral administration of marijuana. Again, it is relatively common for naive consumers of edible products to overdose because the subjective effects hit long after a ballistic, irreversible drug administration has been accomplished.

A recent paper on the use of e-cigarettes for cannabis delivery (Etter, 2015) piqued my interest because it suggested that experienced cannabis smokers did not really like the e-cigarette delivery all that much.

Presentations at the recent CPDD meeting referred to the fact that nicotine seekers who use e-cigarette devices have to learn to adjust their inhalation behavior relative to their tobacco smoking. This is described in a paper that I located:

Farsalinos KE, Spyrou A, Stefopoulos C, Tsimopoulou K, Kourkoveli P, Tsiapras D, Kyrzopoulos S, Poulas K, Voudris V. Nicotine absorption from electronic cigarette use: comparison between experienced consumers (vapers) and naïve users (smokers). Sci Rep. 2015 Jun 17;5:11269. doi: 10.1038/srep11269.

Farsalinos15-nicotine-experiencedvapersThe authors examined e-cigarette (EC) use in groups of ex-smokers who had quit and had been using ECs for at least a month and another group of smokers who were not EC users (available for free at PMC here). Subjects were asked to take 10 puffs from a standardized EC device in the first five minutes and then use it at their own discretion for another hour. The study sampled their blood for nicotine levels that were achieved across the study and the key figure from this paper is depicted here. As you can see, the experienced EC users (vapers) reached higher plasma nicotine levels than did the EC-inexperienced smokers. Each group averaged the same number of puffs, around 85-90, but the experience vapers took longer puffs (3.5 vs 2.3 seconds).

The simple interpretation is that if nicotine amount is a function of vapor cloud volume, and delivery across the lungs depends on retention time within the lungs, then longer puffs would result in greater nicotine delivery. The slightly more complex issue, mentioned at the CPDD annual meeting but not addressed in this paper, is that the rate at which a user inhales can be important. The idea is that if you pull too much of the EC vehicle across the heating element it can cool the element, resulting in lower nicotine yield.

Bottom line, EC inhalation for maximum nicotine yield and tobacco smoke inhalation for maximum nicotine yield may require a different inhalation approach.

This then reminds us that when ECs are adapted for crude cannabis extracts or even other drugs, it will require users to learn to adapt their behavior for idealized drug yield before we truly understand the risks. An initial report like Etter (2015) showing cannabis users don’t like to use ECs to deliver THC as well as they like to smoke cannabis need to be viewed in that light

June 28, 2013

RFAs for Tobacco Control “Regulatory Science”

Filed under: NIH, Tobacco/Nicotine — Tags: , — mtaffe @ 10:33 am

One of the more interesting symposia at the recent CPDD meeting focused on a new drive by the FDA and NIH to respond to the 2009 Family Smoking Prevention and Tobacco Control Act.

In short, the FDA is seeking to generate scientific information to guide and justify any steps they take to regulate tobacco products in the future. The money is apparently coming from taxes on said products so this will not involve any new appropriates to the NIH…from what I understood the NIH will simply be administering the research process.

There are now a flurry of RFAs:

are the standard R-mechanism ones.

For the R01s, due dates are January 15, 2014; June 17, 2014, January 16, 2015 and they anticipate devoting $11 Million to 20 awards.

It gets even better since they’ve thrown up some RFAs for K mechanisms

including the K99/R00. Serious stuff.

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