This news story covers the recent FDA approval of the drug varenicline for smoking cessation. This drug may help quell nicotine cravings by binding to the nicotine receptors in the brain and only partially activating them, so there is less stimulation than by nicotine itself. Varenicline (trade name Chantix) was given priority status and fast-tracked for approval due to the “significant improvement” over existing therapies for smoking cessation; however, the long-term benefit of this drug over existing anti-smoking therapies is not that impressive. This drug’s performance is not much better than smoking cessation rates for bupropion (marketed as Zyban) versus placebo in other randomized controlled studies. Varenicline may be an option for people who have not been able to quit smoking using bupropion or other anti-smoking therapies, however, there is more information on the long-term safety of bupropion.
The recent approval of varenicline was largely based on two double-blind, randomized studies of 2000 smokers in which the drug was compared with bupropion and a placebo. The studies were both funded by Pfizer, maker of varenicline. The story correctly avoids the use of only relative numbers (which Pfizer emphasizes in its press release) and presents longer-term (one year) abstinence rates, which are important for evaluating smoking cessation therapies. However, reports of side effects in this story are very limited. The incidence and severity of nausea, the most common side effect and the only one listed in this story, is not mentioned. There is also no comparison of how tolerable were the side effects from varenicline and bupropion.
There is acknowledgment in this story that the long-term success rate for smoking cessation may be due to a number of combined therapies, though there is also a warning that varenicline should not be taken with other smoking-cessation products. While counseling and other behavioral support are briefly mentioned as aiding smoking cessation, it is not explained if counseling was part of the long-term follow up treatment in studies evaluating varenicline. The Pfizer press release announcing the recent FDA approval of this drug also mentions plans to offer users an interactive smoking cessation support program.
There is no discussion of the cost of this anti-smoking therapy (which must be taken twice daily) or a cost comparison with existing treatments; however, projected sales for Pfizer are mentioned.
The story does not provide the cost of varenciline (which must be taken twice daily), or cost comparison with existing treatments.
The story frames the data appropriately. The story avoids the use of only relative risk that the company emphasizes in its press release. The drug was given priority status and fast-tracked for approval due to the “significant improvement” over existing therapies for smoking cessation, which weren’t all that signficant.
Nausea is the only harm discussed, though there is no mention of the rate or severity of nausea in the treatment and placebo groups, or if participants dropped out of the study due to this side effect. Other side effects of the medication included headaches, insomnia and stomach problems, which are also not mentioned in the story.
The story only briefly mentions clinical evidence, and provides an incomplete discussion of the design of the Chantix trials. The numbers were from two fairly well-designed, randomized, double-blind trials (2000 participants), which the story fails to note. Abstinence rates were evaluated between varenicline (Chantix), bupropion (Zyban) and placebo groups at 12 weeks, then continuous abstinence for another 40 weeks. Incidence of nausea, the most common side effect, is not mentioned. There is acknowledgment in the story that the long-term success rate for smoking cessation may be due to a number of combined therapies, including non-drug behavioral treatment. The drug was given priority status and fast-tracked for approval due to the “significant improvement” over existing therapies for smoking cessation, which weren’t all that signficant.
There does not seem to be evidence of disease mongering. The story uses federal agency data to describe prevalence of smoking and numbers desiring to quit.
The study was funded by Pfizer, which is noted in the story. The story mentions that the inventor of the drug is an employee of Pfizer, so his testimonial on its effectiveness may be somewhat biased.
The story mentions other drug treatments such as nicotine replacement therapies and bupropion. There is some discussion of non-drug methods of smoking cessation (e.g. behavioral counseling ) with regards to long-term abstinence.
The story mentions recent FDA approval of varenicline for smoking cessation, however, we don’t know if it is available (presumably not as there is no price yet) or when it will become available.
The story explains how this drug differs from nicotine replacement, and that it is different from bupropion. Varenicline binds to the nicotine receptor and only partially activates it so there is less stimulation than by nicotine itself. One of the downstream events from nicotine receptor binding is dopamine release in the parts of the brain wired for reward.
There is no evidence that the story relied solely on a press release. The author cites, responsibly, multiple national experts who put the drug in perspective.