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Pendharkar and roman: risks and rewards of e-cigarettes remain unknown

Tobacco other than cigarettes: approximation of rates

Re E cigarette risks waft into council, March 31.

As respirologists, we are frequently asked our opinion on e cigarettes. There appears to be some potential positives. While one study suggested these devices could help smokers quit tobacco, a more recent small study questions this claim.

When you consider the countless harmful chemicals in tobacco smoke, a nicotine delivery option without the tar and other combustion byproducts seems a healthier way to satisfy a nicotine addiction. However, our concerns about e cigarettes include the absence of long term data on their safety and efficacy as smoking cessation aids, and the lack of regulation regarding their production, sale and use. We were encouraged to hear that Calgary city council recently voted to study e cigarettes with a view to developing local regulations.

The safety concerns are not insignificant. In 2009, the U.S. Food and Drug Administration warned that a cartridge from a leading brand of e cigarettes contained a small amount of diethylene glycol, a chemical used in antifreeze, as well as levels of carcinogens and toxic chemicals.

Propylene glycol, in which the nicotine in e cigarettes is suspended, has been linked to adverse changes in lung function. While the short term effects of e cigarettes on lung health may be comparable to or less than conventional cigarettes, there are no studies looking at longer term effects on lung or cardiovascular health.

In the current climate of unregulated products, individuals can select from over 400 devices and compounds, delivering as much as 10 to 15 fold more nicotine than a cigarette. It is difficult to base a clinical recommendation on such highly variable products.

The high concentration of nicotine in the substances used to fill these devices can be profoundly toxic when taken orally. The exotic flavours are attractive to children and the manufacturers are not required to have childproof caps. As use becomes more prevalent, we will likely see cases of serious toxicity or death due to nicotine overdose. These products must be regulated to mitigate this important public health risk.

There is also a lack of high quality evidence to support the use of e cigarettes as smoking cessation aids. Some smokers view e cigarettes as a risk free alternative. But we do not know how e cigarettes compare in effectiveness and safety to pharmacologic aids. In the absence of high quality clinical trials to address these and other important questions, we are unable to provide our patients with advice concerning the efficacy or safety of e cigarettes.

We see many parallels between e cigarettes and herbal medications their use is becoming more common, they are unregulated and people who take them often consider them harmless.

Perhaps we will find that e cigarettes may be useful in the right context and with the right oversight, but also are not without risk. There is much more work to do before we can comfortably recommend e cigarettes as smoking cessation aids, including regulation to prevent risks and a well designed randomized control trial assessing their safety and effectiveness compared to other smoking cessation aids.

We applaud city council for taking the lead in attempting to address this complex issue.

Dr. Sachin R. Pendharkar and Dr. Michael Roman are respirologists and assistant professors at the University of Calgary.