Thursday, June 28, 2012

Smokeless Reduces Smoking in Small Clinical Trial


Dr. Dorothy Hatsukami and colleagues have published a small clinical study documenting that smokeless tobacco products appeal to and satisfy smokers, reducing smoking and promoting abstinence.  The research was conducted at the University of Minnesota and the Oregon Research Institute; it appears in Drug and Alcohol Dependence (abstract here). 

Smokers of at least 10 cigarettes a day were recruited in the Minneapolis and Eugene, OR areas; 99 smokers formally entered the intensive 5-week trial (65% were men) and 91 completed it. 

Over two weeks, smokers sampled five products (and flavors): Stonewall dissolvable tobacco (wintergreen, java, natural), Camel snus (frost and mellow), Ariva dissolvable tobacco (wintergreen, java), Marlboro snus (spearmint, peppermint, rich), and General snus portions (unflavored).  A sampling protocol was followed in order to collect information “on relief from withdrawal, relief from craving, ease of use, and general satisfaction and likeability.” 

In the following two weeks, subjects were instructed to quit smoking but were told they could use a preferred smokeless product; three clinic visits were required, for data collection purposes.  A final clinic visit occurred one week later, and a follow-up phone call completed the study at week nine.  During visits, abstinence was verified with an exhaled carbon monoxide test.  Subjects were paid up to $300. 

No subjects chose General for the treatment period; the other four products were each preferred by about a quarter of participants.

At the start of the treatment period, subjects used on average about seven smokeless products daily, and smoked 1-3 cigarettes.  After two weeks, smokeless use dropped to 4-6, while cigarette use was 1-4 daily, depending on the smokeless product.  Camel snus use correlated with the lowest cigarette use.
 
The following table shows the key trial results.  Almost 60% of Camel snus users were cigarette-abstinent during the treatment period, and their continued use of smokeless products was high.  Other products were accompanied by lower abstinence and smaller rates of continued use.  This may be due to Camel’s higher level of available nicotine (1.7 to 2.0 mg. per portion) as measured by Hatsukami, compared to Marlboro (0.1 to 0.4), Stonewall (0.3 to 0.6) and Ariva (0.2).  Camel snus users also had the highest satisfaction scores and the lowest craving scores.


Smokeless Tobacco as a Cigarette Substitute
Product Abstinent During Treatment Period (%)Continued Use After Treatment (%) Continued Use At Week Nine (%)
Camel snus596748
Marlboro snus302617
Stonewall dissolvable294621
Ariva dissolvable253825

Dr. Hatsukami concluded that “smokers who chose the [Camel] snus product with higher nicotine levels tended to report greater craving and withdrawal relief, more satisfaction, smoking less cigarettes and achieving greater short-term abstinence.”  These are important findings, since they validate the effectiveness of smokeless tobacco products as temporary cigarette substitutes. 

This is an excellent study, but one question remains: Were subjects given complete and accurate information about health risks from smokeless tobacco use and smoking?  Institutional Review Boards require full disclosure of this information to research subjects of clinical trials, and the substance and style of this disclosure could have profound effects on the outcome.  A description of this disclosure would have been informative.

Evidence from this clinical trial will be valuable when the FDA reviews applications for modified risk tobacco products.  Dr. Hatsukami is a member of the FDA Tobacco Products Scientific Advisory Committee, adding to the work’s credibility. 

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