Wednesday, April 21, 2010

New Study Finds No Effect of Bupropion (Zyban) on Craving to Smoke; Will Anti-Smoking Groups Call for Zyban to Be Pulled Off Market?

A new study published in the current issue of the journal Nicotine and Tobacco Research finds that the drug bupropion (Zyban), which is approved by the FDA for the treatment of smoking cessation and whose use is widely promoted by anti-smoking groups, had no effect on suppressing the craving to smoke among smokers in a randomized, double-blind, placebo-controlled clinical trial (see: Madden GJ, Kalman D. Effects of bupropion on simulated demand for cigarettes and the subjective effects of smoking. Nicotine and Tobacco Research 2010; 12(4):416-42).

According to the paper: "The effects of bupropion on simulated demand for cigarettes were investigated in a placebo-controlled double-blind clinical trial. Participants reported the number of cigarettes they would purchase and consume in a single day at a range of prices. The effects of medication on the subjective effects of smoking were also explored. ... Demand for cigarettes was well described by an exponential demand equation. Bupropion did not significantly decrease the maximum number of cigarettes that participants said they would smoke in a single day nor did it significantly alter the relation between price per cigarette and demand. ... Medication group had no effect on any subjective effects of smoking."

The paper concludes: "Bupropion had no significant effects on demand for cigarettes."

The Rest of the Story

The results of this study stand in stark contrast to those of a recent study which found that electronic cigarettes significantly suppress the desire to smoke.

That study, published in the April issue of Tobacco Control, demonstrated that electronic cigarettes are effective in suppressing the desire to smoke, have similar efficacy to nicotine inhalers, and are more pleasant to use than the nicotine inhaler (see: Bullen C, McRobbie H, Thornley S, Glover M, Lin R, Laugesen M. Effect of an electronic nicotine delivery device (e cigarette) on desire to smoke and withdrawal, user preferences and nicotine delivery: randomised cross-over trial. Tobacco Control 2010; 19:98-103).

While I am not arguing here that Zyban should be taken off the market or that it has no effect in treating smoking cessation, I am pointing out that there is credible scientific evidence that electronic cigarettes are more effective than Zyban in suppressing the desire to smoke. Anti-smoking groups continue to argue that electronic cigarettes must be taken off the market because there is no evidence that they are effective in treating smoking cessation. However, the evidence right before their eyes suggests that these products are more effective than those approved by the FDA to treat smoking cessation.

In other words, I do not truly believe that it is the scientific evidence that these anti-smoking groups are concerned about. They continue to claim that we have no idea what is in electronic cigarettes when in fact, the constituents of these products have been studied extensively. In fact, we know far more about the constituents of electronic cigarettes than we do about the constituents of regular cigarettes. The evidence is not what these groups are concerned about. What I believe they are concerned about is the idea that it could be beneficial to someone's health to go through the motions of what looks like smoking. I believe the battle is a purely ideological one, not a scientific one.

In addition, I think the battle is a financial one, as the groups calling for a ban on electronic cigarettes have received funding from pharmaceutical companies which stand to lose severely if electronic cigarettes are shown to be more effective than pharmacotherapy in facilitating smoking cessation.

Zyban is manufactured by GlaxoSmithKline, and in fact, several of the anti-smoking groups supporting a ban on electronic cigarettes have a financial interest in Glaxo by virtue of having received significant funding from this company. For example, the American Academy of Pediatrics, which called for a ban on electronic cigarettes, has received sponsorship support from GlaxoSmithKline for its annual conference at the "gold" level. Other groups which have called for a ban on electronic cigarettes - the American Lung Association, American Cancer Society, and Campaign for Tobacco-Free Kids - have also received financial support for their activities from Glaxo.

This story also explains why it is so inappropriate for the FDA Tobacco Products Scientific Advisory Panel to contain members who have financial conflicts of interest with Big Pharma. They cannot objectively review data on the effectiveness of electronic cigarettes and pharmacotherapy for smoking cessation, a key issue which the FDA will need to consider. The chair of the Committee - Dr. Jonathan Samet - has received grant support from GlaxoSmithKline. In addition, the organization that he directed - the Institute for Global Tobacco Control - is funded by GlaxoSmithKline and Pfizer. A second panel member - Dr. Neal Benowitz - has also consulted for GlaxoSmithKline. And worst of all, a GlaxoSmithKline consultant - Dr. Jack Henningfield of Pinney Associates - was appointed to the panel.

The rest of the story is that despite the claims of anti-smoking groups that nothing is known about the safety or effectiveness of electronic cigarettes, there is in fact evidence that these devices may actually be as effective or even more effective than approved pharmaceutical therapies for decreasing the desire to smoke, probably because they address the behavioral and not just pharmacologic aspects of the addiction. But anti-smoking groups, I am convinced, are not interested in the actual scientific evidence. Like the data on smoking bans and heart disease, these groups will simply ignore data that does not conform to their pre-conceived ideas.

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