Smoking cessation medicines such as nicotine replacement therapy, varenicline and bupropion have consistently been shown to increase quit rates in randomized placebo-controlled clinical trialsâ€¦.generally regarded as the best way to find out if a medicine does what it is supposed to and is safe. However, some survey studies, which asked people how they tried and succeeded in quitting did not find that people who used these same medicines had higher quit rates. A number of reasons have been put forward to explain these different results in different types of study. These include the possibility that people who volunteer for clinical trials may be different in some way from people who try the same medicines in the "real world" (e.g they might be more addicted). Another possible explanation is that smokers participating in surveys in which they are asked to recall previous quit attempts may forget some attempts where they tried on their own, but are more likely to recall quit attempts where they used a medicine.
A large study that sheds light on these issues was recently published in the journal Addiction. Dr Karin Kasza and colleagues surveyed over 7000 smokers every 6 months from 2002 to 2009, asking them about their quit attempts since their last interview. They found that, consistent with evidence from randomized controlled trials, smokers in the United Kingdom, Canada, Australia and the United States are more likely to succeed in quit attempts if they use varenicline, bupropion or nicotine patch, compared with trying to quit without a medicine. They also found that quit attempts that did not use a medicine were more likely to be forgotten at subsequent interviews, explaining why previous studies did not find a higher quit rate with medicines (failed attempts without medication more likely to be forgotten than failed attempts with medicine). It is reassuring to know that the pattern of results found in clinical trials also applies in the "real world" too, and that these medications are effective in helping smokers quit.
Last year a review of clinical trials of varenicline (Chantix) concluded that this smoking cessation medicine may cause an increased risk of serious cardiovascular events among smokers trying to quit and this was widely reported, including on WebMD . However, last week a new study , including all 22 placebo-controlled trials of varenicline published to date, found no significant increase in serious cardiovascular problems associated with use of varenicline. In this study a serious cardiovascular event included any ischaemic or arrhythmic adverse cardiovascular event (myocardial infarction, unstable angina, coronary revascularisation, coronary artery disease, arrhythmias, transient ischaemic attacks, stroke, sudden death or cardiovascular related death, or congestive heart failure). Overall, the study found that 0.63% (34/5431) of people using varenicline experienced a serious cardiovascular event, as compared with 0.47% (18/3801) of those using placebo pills. This new study possibly came to a different conclusion than the previous review on this topic because it focused on events occurring while people were taking the drug and for 30 days thereafter. The previous study included events occurring throughout the whole duration of follow-up and did not correct for the fact that varenicline treated patients were more likely to participate in the follow-ups (and therefore report events), partly because they were much more likely to quit smoking. The study authors, Drs Judith Prochaska and Joan Hilton of the University of California, concluded that, "Our meta-analysis of treatment emergent, cardiovascular serious adverse events, ... indicates that the risk of these events associated with varenicline use is small, and statistically and clinically insignificant." I wonder if WebMD is going to report this new finding?View Thread
More addicted smokers (i.e. those who smoke more per day and have their first smoke soon after waking in the morning) can still succeed in quitting smoking. But the evidence suggests that these smokers will likely experience stronger cravings and withdrawal symptoms and therefore it will be a tougher task. But I just want to be clear that it is still doable, and most smokers, by continuing to try, will succeed in quitting. We know that certain activities will increase your chances of quitting sooner rather than later and these activities may be more important for more addicted smokers. They include getting access to some counseling support (which in the USA can be accessed for free by calling 1-800-QUIT NOW), using one (or more) of the FDA-approved smoking cessation medicines, and continuing with these for as long as it takes. You CAN do it and these activities will increase your chances.View Thread
One of the most widely used questionnaires designed to measure the strength of addiction to cigarettes is called the "Fagerstrom Test for Nicotine Dependence" or FTND . It is a 6-item questionnaire, yielding a score from 0-10, with a higher score implying stronger addiction. Dr Karl Fagerstrom, the Swedish researcher who originally developed the FTND recently published a study that examined the relationship between baseline (pre quit attempt) FTND score and success in quitting smoking among almost 5000 smokers who participated in placebo-controlled trials of varenicline (marketed as Chantix in the USA). The study confirmed that smokers with lower pre-quit FTND scores had a much better chance of successfully quitting 6 months later. For example, smokers with the lowest scores (0-1) were twice as likely to successfully quit smoking as those with the highest scores (9-10). The study also found that a shorter, two-question version was just about as predictive of success in quitting smoking. The two key questions were: 1. How many cigarettes per day do you smoke? 2. How soon after you wake do you smoke your first cigarette of the day? Those who smoke more than 30 cigarettes per day or smoke within 5 minutes of waking in the morning have a lower quit rate than those who smoke less than 11 cigarettes per day and typically don't smoke their first of the day until over an hour after waking in the morning. It appears that these two questions on their own can give a reasonable but fairly rough guide to how addicted a smoker is. I say "fairly rough" because even among those scoring a zero on these addiction assessments (i.e. the least addicted), the six month quit rate among those receiving placebo in the clinical trials was only twenty percent. This suggests to me that significant addiction is present among people who smoke less than 11 cigarettes per day. It also suggests that we need some additional questions that can help measure level of addiction at the low levels of daily cigarette consumption (i.e. <11 per day). It is unclear whether an individual actively delaying the first smoke of the day and reducing their daily cigarette consumption over time can make themselves "less addicted". It is possible, if sustained over a reasonably long period (i.e. greater than a month). However, perhaps a more practical use of these types of quick addiction assessments is to guide the smoker about whether they would likely benefit from assistance in quitting (e.g. counseling and/or medication). It seems that people who smoke just a few cigarettes per day and don't smoke within an hour of waking in the morning may have a good chance of success by picking a day and making a serious quit attempt on their own. Heavier smokers may be more likely to benefit from additional assistance. However, in this recent study, even those who had a zero score on the addiction questionnaires were more than twice as likely to successfully quit smoking for 6 months if they received varenicline as compared to those receiving placebo (47% v 20%).View Thread
Nicotine has an average "half-life" of 2 hours in the human body, but it can range from 1 to 4 hours in different people/circumstances. A VERY high blood nicotine concentration at the end of a smoking day might be 80 ng/ml. For the average smoker, therefore, the blood nicotine concentration will be down to negligible levels (<1ng/ml) within 24 hours. Cotinine has a typical half life in the range 16-24 hours, so it could take over a week for the cotinine level of a heavy smoker (could be over 500 ng/ml) to get down to the sorts of levels that could conceivably be caused by exposure to environmental tobacco smoke pollution (i.e. other peoples smoke). This all assumes the individual is not continuing to use any nicotine-containing products.View Thread
A new study was published in the New England Journal of Medicine last week by Dr Tim Colemen (University of Nottingham, UK) and colleagues, examining whether daytime nicotine patches (initially for one month) increase quit rates among pregnant smokers. This was a large and thoroughly conducted study. The investigators informed around 21,000 women about the trial, screened 2410 women who were initially interested, and finally recruited 1050 pregnant smokers to the study. The women included in the trial had an average age of 26, had smoked 20 cigarettes per day prior to pregnancy and were smoking an average of 14 cigarettes per day when recruited to the study, approximately 16 weeks into the pregnancy. The majority of the women smoked their first cigarette of the day within 15 minutes of waking in the morning, suggesting that most were highly addicted to nicotine. All of the women were given around 45 minutes of face-to-face smoking cessation counseling at the start of the study, and then 2-3 sessions of telephone counseling. All the women were given a month supply of skin patches, but half were given patches containing nicotine, and half received patches not containing nicotine ("placebos"). Neither the women nor the midwives were told which type of patches each woman received ("double blind"). Those women who were quit at one month follow-up were offered another month of patches. The main aim of the study was to find out whether using nicotine patches increased quit rates. At one month follow-up, more women receiving nicotine patches than placebo patches had quit (21% v 12%). However, only 7% of the nicotine patch group and 3% of the placebo patch group continued with the second month of patches. By delivery of the babies, there was no significant difference in quit rates between the two groups (9% v 8%). The study also measured a range of side effects and pregnancy outcomes and for most of these there were no differences between nicotine and placebo patches. For example, 6% of both groups reported neonatal adverse events, and the birth weight of the babies was very similar in both groups. The authors concluded that adding 15mg daily nicotine patches to brief behavioral counseling for pregnant smokers neither increases the quit rates, nor increases the risk of adverse pregnancy or birth outcomes. A couple of things are striking about the results. The first is that, despite being seemingly highly motivated to quit smoking, less than one in five managed to quit for a month, and less than 10% were quit at the time of delivery (around 5 months after initially trying to quit). The other striking result is the very low compliance with patch use and the low use of additional counseling. 76% of those given placebo patches and 60% of those given nicotine patches used them for less than 15 days. The lower patch use in the placebo group suggests this was not caused by nicotine-related side-effects. Part of this early termination of patch use may be due to a perception that they were not helping to quit smoking, and part may have been (ironically) due to concerns about potential harm to the baby.(Ironic because there is much greater harm to the baby from continued smoking). In particular, it is likely that women would have stopped using the patches when they had a smoking lapse, because of (misplaced) concern that smoking while using the patch may be particularly harmful. The women were also given the opportunity for additional face-to-face counseling sessions but only around 10% did so. Clearly the search must continue for widely applicable and effective ways to help pregnant smokers to quit. View Thread
A new research study has recently been published in the journal Addiction, by Professor Ron Borland and an international team of researchers which gives perhaps the best data on the smoking cessation process yet seen. This study conducted telephone interviews with approximately 2000 smokers in Australia, Canada, UK and USA each year from 2002 to 2008. They attempted to recall those who quit smoking in subsequent years, resulting in a sample of almost 22,000 people. At each interview, participants were asked detailed questions about their quit attempts both in the past and since their last interview. At the first wave of interviews, 82% reported having made a prior quit attempt, reaching 94% among those who participated in all 7 waves of interviews. 43% reported a quit attempt in the prior 12 months. Over a 5 year period, 69% of those starting as smokers had reported quit attempts of at least a month, and overall 16% managed to quit and remain quit for at least a year. The study shows that quit attempts are very common, with around 40% of smokers trying to quit each year, each making an average of 2 attempts per year. Thoughts of quitting that do not result in serious attempts are even more common, with an additional 30% of smokers having "serious thoughts" about quitting but not making a serious attempt. One other finding from this study is that smokers tend to forget their short-lived quit attempts, with 20% being forgotten within a year. Based on detailed analyses of their longitudinal data, the authors estimate that the average 40 year-old smoker who started smoking in their teens will have made more than 20 failed quit attempts. More than half of current smokers have succeeded in quitting for at least a month, and a majority of these for over 6 months. This study, perhaps the most detailed of its kind, reminds us that quitting smoking is best conceptualized as a process requiring efforts, often repeated, over a long period of time, rather than as a single event. Reference: Borland et al (2012). How much unsuccessful quitting activity is going on among adult smokers? Data from the International Tobacco Control Four Country Cohort Study. Addiction, 107, issue 3. P673-682.View Thread
Check out my comments on the recent study claiming to show that nicotine replacement therapy does not help smokers to quit. That study had many weaknesses and was a study of long term relapse rather than a study of quitting. It is no surprise that taking NRT for a couple of months 4 years ago has little imact on your chances of relapsing this year.View Thread