Varenicline ( Chantix ) does not produce depression or suicide: new study

The smoking cessation medicine, varenicline, has proven safe and effective in numerous placebo-controlled trials, but in the post-marketing phase there were numerous reports of patients experiencing “neuropsychiatric effects” ranging from poor concentration all the way to suicide. In July 2009, the US Food and Drug Administration (FDA) required the manufacturers of both varenicline and bupropion to add new “boxed warnings” to the product labeling based on continued review of postmarketing adverse event reports. These issues have been discussed on this blog before and many readers have provided very useful comments based on their own experience (you can find these by typing “varenicline “ in the box on the right and clicking on “search health experts”).

Today a major new study of this issue was published in the British Medical Journal (BMJ) by Professor Gunnell and colleagues of the University of Bristol in England. One of the main strengths of this study was its size. The study used the UK General Practice Research Database (GPRD) which collects all the clinical data and prescribing information from 500 family doctors (GPs) throughout the UK (covering 3.6 million patients). They identified all adult patients who were prescribed a smoking cessation medication between September 2006 and May 2008 and then searched their records for occurrence of suicide, self-harm (non-fatal self injury), and being prescribed an antidepressant medication in the following 6 months. Overall 80,660 patients were included in the study (63,265 on NRT, 6422 on bupropion and 10,973 on varenicline). So this is by far the largest and most thorough study examining this issue.

The researchers recognized that smokers are at increased risk of suicide and that smoking cessation itself can cause mood disturbance, and so they decided to compare the rates of adverse events in patients using varenicline with patients using nicotine replacement therapy (NRT) or bupropion. This is an excellent way to assess the risks of varenicline as compared with comparable patients trying to quit smoking, particularly as there is no concern about NRT causing depression or suicide. Another strength of this study was that the researchers had access to the patients’ prior medical history and so were able to control for potential differences in the characteristics of the patients using the different treatments.
Overall there were 166 episodes of self harm, 37 episodes of suicidal thinking and 2 suicides during the follow-up period. Both the suicides were in patients who had used NRT (no suicides in the 10,973 patients using varenicline) and there was no statistically significant increased risk of suicide, self-harm, suicidal thoughts, or subsequent use of antidepressants in patients using varenicline or bupropion as compared with NRT. In fact patients prescribed varenicline appear to have a significantly REDUCED risk of needing a prescription for antidepressants during the subsequent months. 208 people died during the follow-up period and patients on varenicline were significantly LESS likely to have died than patients taking NRT (although this analysis only controlled for age and sex and the effect may diminish when a wider array or risk factors are controlled for).
Overall, this large study found only 18 episodes of self harm out of 10,973 smokers prescribed varenicline, a proportion not significantly different from NRT or bupropion. In addition it found that significantly fewer varenicline-treated patients had a subsequent need for antidepressants.

The well controlled placebo-controlled trials found no evidence of varenicline causing more suicidal thoughts than placebo, but patients with serious mental health or medical problems were largely excluded from those studies. This sample, however, was a real world patient sample,. 10% had a history of alcohol misuse, 5% were using antipsychotic medication, 13% anti-anxiety medication and 24% antidepressants. 11% had experienced a previous suicide related event. So when such a large, well-designed study like this finds really no evidence to support the claim that varenicline causes depression or suicide I am inclined to believe the evidence.
I should disclose here that I have done consulting work for manufacturers of all of these products, but none of the authors of this report receive any funding from any of these companies.

This paper provides considerable reassurance over concerns that varenicline causes suicide. The data shows that it does not.

The reference and link for the paper are:

Gunnell D, Irvine D, Wise L, Davies C, Martin RM. Varenicline and suicidal behavior: a cohort study based on data from the General Practice Research database. BMJ 209: 339 (in press)

http://www.bmj.com/cgi/content/short/339/oct01_1/b3805?rss=1

Labels: bupropion, champix, Chantix, depression, Gunnell, jonathan foulds, NRT, self-harm, suicide, varenicline

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FDA: Boxed Warning on Serious Mental Health Events to be Required for Chantix and Zyban

On the first of July, 2009 the U.S. Food and Drug Administration issued additional information for healthcare professionals and announced that additional warnings will be required on the boxes of smoking cessation aids varenicline (Chantix in U.S.) and bupropion (Zyban, and generics in U.S.) and for the use of bupropion as an antidepressant (Wellbutrin and generics in the U.S.). The advisory is copied in full below and the link is provided. It highlights the risk of serious neuropsychiatric symptoms in patients using these products. These symptoms include changes in behavior, hostility, agitation, depressed mood, suicidal thoughts and behavior, and attempted suicide.

I’ll give my comments on this in my next posting.

Link to FDA advisory (cut and paste into your browser if link not active):

http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm170100.htm


"Information for Healthcare Professionals: Varenicline (marketed as Chantix) and Bupropion (marketed as Zyban, Wellbutrin, and generics)

FDA ALERT [7/1/2009]: 
FDA has required the manufacturers of the smoking cessation aids varenicline (Chantix) and bupropion (Zyban and generics) to add new Boxed Warnings and develop patient Medication Guides highlighting the risk of serious neuropsychiatric symptoms in patients using these products. These symptoms include changes in behavior, hostility, agitation, depressed mood, suicidal thoughts and behavior, and attempted suicide. The same changes to the prescribing information and Medication Guide for patients will also be required for bupropion products (Wellbutrin and generics)that are indicated for the treatment of depression and seasonal affective disorder.

The added warnings are based on the continued review of postmarketing adverse event reports for varenicline and bupropion received by the FDA. These reports included those with a temporal relationship between the use of varenicline or bupropion and suicidal events and the occurrence of suicidal ideation and suicidal behavior in patients with no history of psychiatric disease. Some of these cases may have been confounded by symptoms typically seen in people who have stopped smoking and are experiencing withdrawal from nicotine.

Healthcare professionals should advise patients to stop taking varenicline or bupropion and contact a healthcare provider immediately if they experience agitation, depressed mood, and any changes in behavior that are not typical of nicotine withdrawal, or if they experience suicidal thoughts or behavior. If varenicline or bupropion is stopped due to neuropsychiatric symptoms, patients should be monitored until the symptoms resolve.

Family members and caregivers should also be alerted to the potential for changes in mood or behavior and contact the health care provider if they observe these changes in the person taking varenicline or buporpion. Varenicline and bupropion are effective smoking cessation aids. The possible risks of serious adverse events occurring while using varenicline or bupropion should always be weighed against the significant health benefits of quitting smoking. The health benefits of quitting smoking include a reduction in the chance of developing lung disease, heart disease, or cancer. 
 
This information reflects FDA’s current analysis of data available to FDA concerning these drugs. FDA is not advising practitioners to discontinue prescribing these products. FDA intends to update this sheet when additional information or analyses become available.
To report any unexpected adverse or serious events associated with the use of these drugs, please contact the FDA MedWatch program using the information at the bottom of the page.

FDA last informed healthcare professionals and patients of the addition of suicidal ideation, attempted and completed suicide, changes in behavior, agitation, and depressed mood in the WARNINGS and PRECAUTIONS sections of the varenicline prescribing information and patient Medication Guide on May 16, 2008. Varenicline (marketed as Chantix) Information FDA is now requiring the addition of this information to the BOXED WARNING and to the Medication Guides for patients who are prescribed varenicline and bupropion under the authorities provided in the Food and Drug Administration Amendments Act (FDAAA).

Recommendations and Considerations for Healthcare Professionals
It is important to discuss the possibility of serious neuropsychiatric symptoms in the context of the benefits of quitting smoking with patients before prescribing these medications. Varenicline and bupropion are both effective smoking cessation aids and the health benefits of smoking cessation are immediate and substantial.
Healthcare professional should monitor all patients taking varenicline and bupropion for serious neuropsychiatric symptoms. These symptoms include changes in behavior, hostility, agitation, depressed mood, suicidal ideation, suicidal behavior and attempted suicide. These symptoms have occurred in patients without pre-existing psychiatric illness and have worsened in some patients with pre-existing psychiatric illness. In most cases, neuropsychiatric symptoms developed during treatment with varenicline or bupropion but in others, symptoms developed after stopping drug treatment.
Patients should be informed that it is not unusual to have symptoms such as irritability, feeling anxious, depressed mood and trouble sleeping when they are withdrawing from nicotine, independent of whether they are taking varenicline or bupropion.
Patients with serious psychiatric illness such as schizophrenia, bipolar disorder, and major depressive disorder, may experience worsening of their pre-existing psychiatric illness while taking varenicline or bupropion.
Patients who discontinue treatment because of neuropsychiatric events should continue to be monitored until symptoms resolve. Although symptoms resolved after treatment was stopped in many cases, there were also some cases where the symptoms persisted.

Information for healthcare professionals to discuss with patients, family members, and caregivers:
Quitting smoking can decrease the chances of lung and heart disease and getting cancer. These important health benefits should be weighed against the small, but real, risk of serious adverse events with use of varenicline or bupropion.
Worsening or recurrence of psychiatric illness. Patients should be told that some patients taking varenicline or bupropion have experienced worsening of their psychiatric illness, even when the illness was under control and some patients have experienced a recurrence of a previous psychiatric illness when taking these drugs for smoking cessation.
Unusual changes in mood and behavior. Patients should be instructed to contact their healthcare provider immediately if they observe or develop thoughts about suicide or attempting suicide, feel agitated, aggressive or violent and other unusual changes in mood or behavior.
Some symptoms are to be expected when quitting smoking. Patients should be told that it is not unusual to have symptoms such as irritability, feeling anxious, depressed mood and trouble sleeping when they are withdrawing from nicotine, independent of whether they are taking varenicline or bupropion and that vivid, unusual, or strange dreams may occur while taking Chantix and are not a cause for alarm.
Discuss other methods of quitting smoking if it is decided that varenicline or bupropion are not the best treatment option
Background Information and Data
FDA first informed the public about the possibility of serious neuropsychiatric symptoms with varenicline in the November 20, 2007 FDA Early Communication About an Ongoing Safety Review. A complete history of related communications on varenicline and bupropion can be found at: Varenicline (marketed as Chantix) Information Since that time, information about serious neuropsychiatric symptoms in patients taking varenicline has been added to the POST-MARKETING EXPERIENCE section of the prescribing information.
As FDA received additional information the suggestion of a possible association between both varenicline and bupropion (which was evaluated as a comparator to varenicline) and serious neuropsychiatric symptoms, in both patients with and those without previous history of psychiatric illness, became more evident as its review progressed. As a result, FDA has required the manufacturers of the smoking cessation products varenicline, and bupropion to add information regarding neuropsychiatric symptoms to the Boxed Warning, and Warnings sections of the varenicline and bupropion prescribing information and update the Medication Guides for patients so that healthcare professionals and patients can be more alert to these issues.

A summary of the data from FDA’s review of varenicline and bupropion were published in FDA Drug Safety Newsletter, Volume 2, Number 1, 2009. This analysis was for all reports received by FDA from the time of marketing approval to November 2007. Access to the article is provided in the link below. FDA has continued to receive reports of neuropsychiatric events in association with use of varenicline and bupropion since the data cut off date for the analysis presented in the Drug Safety Newsletter analysis.
 FDA Drug Safety Newsletter Volume 2, Number 1, 2009 - PDF."

Labels: bupropion, champix, Chantix, Chantrix, jonathan foulds, smoking cessation, varenicline, Zyban

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Chantix side effects

Varenicline (AKA Chantix) is a prescription-only smoking cessation medicine that has now been on the market for a couple of years. While studies have shown it to be safe and effective, post marketing surveillance (ultimately via reports by users) have raised concerns that some people may experience severe neuropsychiatric side effects as a result of taking the medicine. In particular, there has been a concern that that people with a psychiatric history (most of whom were excluded from the initial studies) may be at risk if neuropsychiatric symptoms such as depressed mood, agitation, lapses in concentration and suicidal thinking.

There have been relatively few studies of Chantix that included people with a mental illness, so that remains a concern. But last month a new study was published which examined side effects among Chantix users with and without a lifetime history of depression. The study, by Dr Jennifer McClure (Group Health Center for Health Studies, Seattle) and colleagues, compared the rates of side effects among people with (n=661), and people without a history of depression (516) who used Chantix to try to quit smoking while receiving phone and/or internet counseling. The study excluded people suffering from schizophrenia, bipolar disorder, and a few other illnesses. All participants received a telephone interview before starting treatment and 21 days and 3 months after their target quit date (i.e. approx 4 weeks and 13 week s after starting taking Chantix).

The first main finding was that, overall, ratings of symptoms such as depression or stress actually declined after the participants started taking Chantix (and tried to quit smoking), both for those with and without a history of depression. However, smokers with a history of depression felt more tense, irritable, depressed, and confused than those without a history of depression, 21 days after their target quit date (as they did at baseleine), and people with a history of depression who reported depressed symptoms were more likely to report severe depression than those without such a history at 21-day follow-up.

When examining actual change of mood, as compared with baseline, the majority of both groups mood improved after starting Chantix, but 10% of those with a history of depression had a significant worsening, as did 8% with no history of depression. Unfortunately this study was not able to compare these frequencies with people quitting smoking while taking placebo, but earlier placebo-controlled trials have not found a higher rate of mood worsening in Chantix users: quite the opposite.

One other thing worth noting is that both groups had very impressive quit rates, that were actually very slightly higher among those with a history of depression (45%) than those without: (42%) at 3 month follow-up.

So what does all this mean? The study authors interpreted the findings as suggesting that Chantix could be a particularly appealing treatment option for those smokers with a history of depression. Although such smokers are more likely to report common Chantix side effects and nicotine withdrawal symptoms, they had equally high quit rates without clear evidence of a worsening of mood.

So overall these results are somewhat reassuring, and suggest that perhaps we don’t need to be particularly cautious about Chantix use in those with a depression history. However, clinicians, patients and their families and colleagues should continue to monitor patients who are trying to quit smoking, and alert a clinician if a severe worsening of any symptoms appears to be occurring.

Here’s a link to a summary of the study:
http://www.ncbi.nlm.nih.gov/pubmed/19238488?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

Here are links to a couple of previous blog posts on Chantix and its side effects, including comments by many people who either did or did not experience side effects:
http://www.healthline.com/blogs/smoking_cessation/2007/04/chantix-how-does-this-new-quit-smoking.html
http://www.healthline.com/blogs/smoking_cessation/2007/09/does-chantix-cause-mental-health.html

Note: I have done consulting and other paid work for Pfizer, the manufacturer of Chantix, as well as for the manufacturers of other smoking cessation products. See disclosure statement on my homepage at healthline.com.

Labels: champix, Chantix, Jennifer Mcclure, jonathan foulds, side effects, smoking cessation, varenicline

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Chantix safety at the US Veterans Affairs Health Service

The US Department of Veterans Affairs (which provides healthcare for people who have served in the US armed forces) yesterday issues a bulletin on safety issues with varenicline. In addition to covering some of the safety issues that have been discussed previously on this blog, it provided some data on adverse events within the VA.

The report stated that between September 2006 and April 30, 2008 there were a total of 147,718 prescriptions for varenicline (69,765 unique patients) within the VA. As of May 26 2008 , VA healthcare providers had submitted 417 reports on possible adverse events associated with varenicline. The most common type of adverse event was vomiting (95), followed by nightmares/abnormal dreams (82), depression (68), agitation (33), suicidal ideation (31) and hallucinations (25). Other adverse events were reported much less frequently.

So the overall rate of adverse event reports appears to be around 6 per thousand, of which almost half consist of vomiting, abnormal dreams and other non-life threatening symptoms that are recognized as rarely occurring side effects of the drug. Interpretation of the rates of the other (primarily psychological) symptoms needs to bare in mind that the VA healthcare system provides fairly comprehensive and accessible mental health services and the rates of mental health problems in VA patients is therefore known to be higher than in the general population. For example, one recent study found that 40% of male VA patients were suffering from a current mental health disorder.
http://ajp.psychiatryonline.org/cgi/content/full/156/12/1924

With this background, and an annual rate of suicide attempts of 1% among adult smokers, the numbers of patient being reported as suffering these adverse events in the VA system does not appear to be particularly high. One patient was known to have committed suicide in association with varenicline use, and although every case of suicide is tragic, one case in almost 70,000 patients in the VA system is almost certainly less than the background rate of suicide in the VA system among patients not using Chantix. I am not saying that Chantix may prevent these symptoms or behaviors. However, even after allowing for under-reporting of adverse events (which is normal), the frequency with which these events are being reported among Chantix users does not appear to be above the frequency that we would expect these types of events to be occurring in patients not using Chantix (in fact its much lower). What this means to me is that there is nothing in this new data that stands out as a clear signal that Chantix likely caused these events (other than perhaps vomiting and abnormal dreams, which are known to be increased by Chantix).

Of course it is very difficult to interpret adverse event reports, which are not necessarily recorded in a very systematic manner. The data we have so far suggest the following:

1. Prescribers should continue to use varenicline as one of the first-line medicines shown to help treat nicotine dependence.
2. Prescribers should make patients aware of the potential side effects, including the relatively frequent effects that have been shown to be caused by the drug (e.g. mild nausea in around 30% of patients), as well as the much less frequent symptoms that have not been proven to be caused by the drug (e.g. depression).
3. Providers should follow the US Public Health Service Guideline that recommends not only assisting smokers to quit by prescribing an effective medicine, but also arranging follow-up with patients to monitor progress and side-effects etc. Patients should also be told to notify their doctor immediately if they experience any serious side-effects between appointments.
4. Patients should continue to consider varenicline as a safe and effective treatment for nicotine dependence, but should be prepared to keep in contact with their healthcare provider and to report onset of unpleasant/serious symptoms to that provider if they occur.
5. Additional placebo-controlled trials in more typical patient samples should be carried out, to provide further high-quality data on efficacy and safety.

Labels: champix, Chantix, cigarette smoking, jonathan foulds, safety, varenicline

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Chantix (varenicline) Safety

Last week a report was released by an organization called the “Institute for Safe Medication Practices” (ISMP) which claimed to have safety concerns about Chantix (varenicline, also marketed as Champix outside the United States). The Executive Summary of the report made two main recommendations:

1. Chantix should be avoided or used with caution by persons operating aircraft, motor vehicles or other machines (e.g. power stations) where a lapse in alertness or motor control could have serious consequences.
2. Patients and doctors should excercise caution in the use of Chantix (generally) and “consider the use of alternative approaches to smoking cessation.”

Given that most of us drive a vehicle, the report is basically suggesting that varenicline is such an unsafe drug that it should be avoided. These are strong recommendations, and have immediately resulted in the Federal Aviation Authority (FAA) and Federal Motor Carrier Safety Administration (FMCSA) adding varenicline to their list of drugs that should not be used by pilots or truck drivers. The report itself has not been published in a peer-reviewed journal and so it is reasonable to assess the quality of the data on which it was based, and to evaluate whether the recommendations are warranted on the basis of that data.

The ISMP report was based on an analysis of the frequency and type of serious adverse events that have been reported to the US Food and Drug Administration (FDA) about Chantix, in comparison to other drugs. In particular, the report noted that by the 4th quarter of 2007 Chantix “accounted for more reports of serious adverse events in the United States than any other drug.” This amounted to 988 reports about Chantix in the 4th quarter, as compared with 372 (Oxycodone) to 640 (Interferon Beta) reports about the next 5 most reported drugs.

The report then selected a sample (3063) of the total reports (excluding foreign or unclear reports) for slightly more detailed analysis. It noted that a much larger proportion of the reports about Chantix came from consumers (57%) than is typical of other drugs (26%) for which health professionals are the predominant source. The report also noted that a lower proportion of the reports about Chantix (2.5%) reported deaths, as compared with 17% of reports about other drugs.

The report summarized the most frequent medical terms included in the reports about Chantix. By far the most common term used was nausea (593), which was more than twice as common as any other reported symptom. It was also noteable that among the most commonly reported medical symptoms mentioned in the adverse event reports, many are also recognized nicotine withdrawal symptoms (i.e symptoms known to increase when smokers quit smoking, particularly without any treatment medication), such as depression (287), insomnia (242), anxiety (217), and weight increase (141).

Problems with the ISMP report and its conclusions

There are a number of fundamental problems with the quality of the data, analysis and interpretation in the ISMP report. Before discussing some of these, it is worth discussing the way that reports of serious adverse events are delivered to the FDA. There are 4 main sources of reports.

1. Members of the public can send reports directly to FDA, either by mail or via an on-line reporting system (and I have provided the link on previous posts on this blog about Chantix to ensure that reports reach FDA).
2. Health professionals can report adverse events to FDA.
3. Lawyers sometimes report adverse events to FDA.
4. The manufacturer is required to report to FDA any reports that are brought to its attention directly. Those adverse events that are already mentioned on the product labeling are reported on a quarterly basis, and novel symptoms must be reported within 15 days (expedited).

Reports from the first 3 of these sources are entirely voluntary and are made in a rather haphazard way. The ISMP report estimated that typically between 1 and 10% of serious adverse events are actually reported to FDA. It is commonly found that AE reports peak around two years after the launch of a drug, even if the drug becomes used more often thereafter. The purpose of the FDA’s reporting and monitoring system is to facilitate post-marketing surveillance and enable detection of patterns of adverse events that could potentially be caused by a medicine but were not detected in the initial placebo-controlled trials leading to drug approval. The main point here is that these reports are not made in a systematic way, and the frequency of reports can be influenced by factors such as (a) the frequency of use of the drug (b) the novelty of the drug (c) media coverage of the drug and (d) efforts by the company to interact with users in a manner that will lead to them hearing of and therefore being required to report on AEs.

With these factors in mind, here are some of the problems with the ISMP report:

1. The report fails to consider the frequency of the use of the drug when considering the number of adverse events being reported. Since its launch in August 2006 (i.e. less than 2 years), Chantix has been used by an estimated 5.5 million smokers in the United States. In 2007 alone it was used by 3.8 million new patients in the U.S. (6.2 million prescriptions). This is many times more than the other drugs listed in the ISMP report. For example, Etanercept (Enbrel, the drug with the 3rd largest number of adverse event reports to FDA) was launched in 1998, and has been used by a total of 450,000 patients WORLDWIDE in those 10 years. Comparing frequency of adverse events without adjusting for the frequency of drug use is so obviously inappropriate as to cast doubt on the reliability of the report as a whole.
As mentioned briefly in the ISMP report, many factors can affect the frequency of reporting of adverse events to FDA. In the case of Chantix, the widely publicized death of a rock musician (who was tragically shot by a neighbor in Texas) which his partner felt could have been related to Chantix, sparked off widespread media speculation about potential side effects. The manufacturer also offers a number of direct to consumer quit smoking services, including a free telephone hotline called “Get Quit”. Because this hotline is run by the manufacturer, whenever a caller mentions a symptom, they are immediately transferred to the medical department, the details are noted and the information reported to FDA. These events and procedures can have a large effect of increasing the number of serious adverse events reported and this was not adequately considered in the ISMP report. It is noteworthy that 92% of the events analyzed in the ISMP report came via the manufacturer.

2. The report fails to adequately consider the possibility that some of the reported adverse events may have been caused by nicotine withdrawal. The vast majority of those using Chantix were attempting to quit smoking, which itself is known to cause a range of nicotine withdrawal symptoms, including many of the symptoms most commonly reported to FDA and mentioned in the ISMP report (depression, insomnia, anxiety, weight increase). It is entirely plausible that many of these reported symptoms were caused by nicotine withdrawal rather than Chantix. In fact in the placebo-controlled trials of Chantix, withdrawal symptoms were REDUCED in those using Chantix.

3. The report doesn't adequately consider the serious health effects of tobacco dependence. The ISMP report characterizes the other comparison drugs as being “intended for serious illness in patients and have benefits that are accompanied by substantial risks. In comparison, varenicline is intended for use in healthy people to help stop smoking.” Unfortunately this statement indicates a misunderstanding of the nature of tobacco dependence as a serious illness causing the premature death of 50% of continuing smokers, and of the fact that a high proportion of patients using smoking cessation medications are already suffering from or at very high risk for smoking-caused illnesses, including some mentioned as adverse events in the report (e.g. cardiac arrhythmias).

4. The report inaccuratley characterizes the relative efficacy of varenicline versus other treatments. The ISMP report states that Chantix has similar long term quit rates to nicotine gum. This statement contradicts the findings of the new US Public Health Service Clinical Practice Guideline on Treating Tobacco Use and Dependence, which found a mean quit rate of 13.8% with placebo, 19% with nicotine gum and 33.2% with varenicline (p109) and that quit rates with varenicline are significantly greater than with the nicotine patch (p121). This Guideline, written after the recent labeling changes for varenicline, concluded that, “Varenicline is an effective smoking cessation treatment that patients should be encouraged to use.” (p113).

Probably the most basic problem with the ISMP report is its failure to consider the frequency of use of the medicines as a factor influencing the interpretation of the frequency of adverse events reported. It therefore remains unclear whether any of these serious adverse events were caused by varenicline. When added to the other problems of interpretation mentioned above, I prefer to rely on the recommendation of the US Clinical Practice Guideline, which resulted from a very thorough review of the available scientific evidence.

So what does this mean for patients considering quitting smoking? As always, rely on the advice of your own doctor rather than on reports in the media or the internet (including this one!).

The complete ISMP report can be found at:
Strong Safety Signal Seen for New Varenicline Risks
http://www.ismp.org/docs/vareniclineStudy.asp

Previous posts on this blog that are relevant to this issue are:
What is nicotine withdrawal syndrome? 3/6/07http://www.healthline.com/blogs/smoking_cessation/2007/03/what-is-nicotine-withdrawal-syndrome.html
Ten tips for coping with nicotine withdrawal. 3/7/07http://www.healthline.com/blogs/smoking_cessation/2007/03/ten-tips-on-coping-with-tobacco.html
Chantix: how does this new stop smoking medicine work? 4/15/07http://www.healthline.com/blogs/smoking_cessation/2007/04/chantix-how-does-this-new-quit-smoking.html
Can quitting smoking trigger depression? 6/16/07http://www.healthline.com/blogs/smoking_cessation/2007/06/can-quitting-smoking-trigger-depression.html
Chantix and mental illness. 08/12/07http://www.healthline.com/blogs/smoking_cessation/2007/08/chantix-and-mental-illness.html
Two new studies of Chantix (varenicline). 08/19/07http://www.healthline.com/blogs/smoking_cessation/2007/08/two-new-studies-of-chantix-varenicline.html
Does Chantix cause mental health problems? 9/20/07http://www.healthline.com/blogs/smoking_cessation/2007/09/does-chantix-cause-mental-health.html
Chantix (varenicline) safety being reviewed by FDA. 11/21/07http://www.healthline.com/blogs/smoking_cessation/2007/11/chantix-varenicline-safety-being.html
New study of Chantix in comparison with NRT. 11/28/07http://www.healthline.com/blogs/smoking_cessation/2007/11/new-study-of-chantix-in-comparison-with.html
Smoking and suicide. 4/22/08 http://www.healthline.com/blogs/smoking_cessation/2008/04/smoking-and-suicide.html

Full reports on the largest placebo-controlled trials of varenicline can be found via:
http://jama.ama-assn.org/cgi/content/full/296/1/47

Labels: cessation, champix, Chantix, cigarette smoking, jonathan foulds, Nicotine Replacement, safety, varenicline

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Why Chantix may reduce alcohol consumption.

Some of those people who have posted comments on my blog have commented that when they were using Chantix (varenicline) their interest in drinking alcohol or smoking marijuana also decreased. There are a couple of obvious potential mechanisms for that effect. Firstly, we are all familiar with the association between smoking tobacco and other substance use. Smokers are much more likely to take other substances than non-smokers, and when a smoker has a drink it often increases their desire to smoke and vice versa. So Chantix may reduce other substance use simply by helping take out cigarettes as a trigger. In addition, there have been reports that in a small but significant proportion of cases, Chantix use has coincided with a period of low mood or depression. So it is plausible that those affected in this way may lose part of their taste or enthusiasm for a number of activities they had previously enjoyed (including alcohol).

But there is also some evidence from studies of experimental rats, which suggests that varenicline (Chantix) may have a more direct effect on alcohol consumption. Last year, Dr Pia Steenland and colleagues at University of California published a paper in the prestigious journal, “Proceedings of the National Academy of Sciences” Their study found that animals who became used to drinking ethanol (alcohol) and were then treated with varenicline showed reduced alcohol-seeking behavior, and reduced alcohol consumption, without having any effects on water or sugar consumption. The authors concluded that,
“The finding that varenicline decreased ethanol consumption in chronically exposed ethanol-consuming rats suggests that varenicline may serve as a therapeutic treatment to reduce alcohol consumption in alcoholic subjects; however, this remains to be examined.”

This means that these results in animals are suggestive of a potential effect in humans, but proper clinical trials in humans will be needed. So these reports of reduced interest in drinking alcohol among people taking Chantix for smoking cessation, may have a real pharmacological basis that may ultimately be clinically useful for people with alcohol problems.

The full study can be viewed at:
http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17626178

Labels: alcohol problem relapse, champix, Chantix, jonathan foulds, smoking cessation, varenicline

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