Concerns about serious side effects of anti-smoking drug Champix (Chantix-varenicline)

New research in the United States on the anti-smoking drug Champix (Chantix-varenicline) says there have been 3,000 reports of side effects since the drug was approved for use there in 2006.

Champix has been available on the Pharmaceutical Benefits Scheme in Australia since January this year; it is a non-nicotine drug designed to help people to quit smoking.

The results of the research from the Institute for Safe Medication Practices, and Wake Forest University, have meant that doctors are now being warned to closely monitor their patients who are taking the anti-smoking drug.

In a pilot program aimed at identifying new drug risks in adverse drug events reported to the U.S. Food and Drug Administration (FDA), multiple safety problems associated with Champix have been revealed.

The drug has been linked to a wide range of injuries, including serious accidents and falls, potentially lethal cardiac rhythm disturbances, severe skin reactions, acute myocardial infarction, seizures, diabetes, psychosis, aggression and suicide.

Varenicline was approved by the FDA in May 2006, it works by blocking one of the nicotinic acetylcholine receptors in the brain and nervous system, while also providing a nicotine-like effect to help curb withdrawal; it is currently the only marketed and approved drug which acts in this manner.

In the last three months of 2007, varenicline was linked to 988 serious injuries in the U.S. reported to the FDA.

This is far more than any other individual drug in this time period and prompted the FDA to conduct an analysis of all adverse events for varenicline since marketing approval in 2006.

The FDA has recently issued a Public Health Advisory about one of the most marked adverse effects of varenicline, psychiatric symptoms that included "changes in behaviour, agitation, suicidal ideation, attempted and completed suicide".

It appears that from May 2006 to December 2007, the FDA received 227 domestic reports of suicidal acts, thoughts or behaviours, 397 cases of possible psychosis and 525 reports of hostility or aggression - amongst these were 28 cases of suicide and 41 mentions of homicidal ideation, 60 cases of paranoia and 55 cases of hallucination.

However, the drug is also linked to other kinds of serious harm for which no warnings currently exist, either from the FDA or from the manufacturer, Pfizer.

These include 173 serious events involving accidents and injuries, including 28 road traffic accidents and 77 falls, some leading to fractures of rib, facial bones, hand, ankle, spine, and lower limbs, where a variety of potential causes were identified, including loss of consciousness, mental confusion, dizziness and muscle spasms.

There were 148 reports of vision disturbances, including 68 cases described as blurred vision and 26 terms indicating transient or other forms of blindness.

There were 224 reports of heart rhythm disturbances including a sudden loss of consciousness, and 372 reports of a wide variety of movement disorders, including tremors, muscle spasms, twitching, tics, drooling and motor hyperactivity.

There were also 338 cases of hives or swelling of the tongue, face, eyes, lips or other areas and 65 cases were classified as severe and included blisters, exfoliation of the skin and lips, and Stevens-Johnson Syndrome.

The FDA also received 544 reports suggesting varenicline may be related to a loss of glycemic control, including many cases of weight loss or gain that could have alternative causes, but also identified numerous cases of symptoms and laboratory tests consistent with new onset diabetes.

The FDA now says there are safety concerns about the use of varenicline among persons operating aircraft, trains, buses and other vehicles, or in other settings where a lapse in alertness or motor control could lead to massive, serious injury.

The FDA recommends that patients and doctors exercise caution in the use of varenicline and consider the use of alternative approaches to smoking cessation.

The researchers say that while the data does not definitively prove that Champix is the culprit in all the cases, it does give a strong signal.


  1. bec bec Australia says:

    I was on the tablets for less than 2 weeks and I have given up. I use the tablets now if I really need a smoke. They work and they are the best thing that has ever been invented in the way of giving up. Within the first week I did not want to smoke. Although they have serious side effects I did not receive any. Mind you...the information they come with has a warning on them and like anyone should the label before use...or seek medical advice...
    All I want to say is...I'm 24 and have been smoking since I was 11. not good...but now because of these tablets...I will get to spend more healthy times with my son.

  2. Linda Linda Canada says:

    I took Champix a little over a year ago and have had several of the side affects mentioned in the online article - aggression being at the top of the list.  

    As a child I was prone to violent (verbal and minor physical) outbursts - I learned to control that as I grew up.  The past two decades I have often been praised for my caring and patient, loving everyone equally, nature.  

    This past year however all of that has changed.  I do have homicidal, suicidal, vindictive and what I consider to be evil thoughts.  I have a hard job not verbally assaulting those who annoy me - I have day dreams of "getting even" with those who severely anger me.

    This not only worries me that I may lose control and follow through on those feelings - but concerns me that perhaps I will never regain my once happy nature...  

    I have also had blurred vision, heart rhythm irregularities, and respiratory issues (I have been on breathing masks since using champix to quit smoking - and now may have to use a sleeping mask to assist with other related health issues).

    No one has yet to determine if Champix is indeed the culprit of my multiple health issues - but I myself can attest to the fact that I was "fine" and "normal" and until I began the pills last June.  I was a smoker - but a darn site healthier and happier than I am today.

    I would warn all people who are contemplating taking this drug to quit smoking - try everything else first - use as a last resort - and be very aware of the side affects.

  3. Michelle Michelle Canada says:

    Well I have been on Champix for a week now - and I have to say I am seriously considering coming off of it.  While it is helping with cravings, it is making me emotional and I am losing sleep.  I am WIDE awake at night, invasive thoughts about the past, things that I dealt with years ago coming back to haunt me.  I have tried shifting my evening pill earlier, it doesn't seem to be helping.  I am not working at my optimum, I have trouble concentrating on work, creativity has been zapped (that is my living) and I am very short tempered. But what I think is the worst is that I have begun internally blaming my spouse for things which normally I would work through or excuse.  I was in tears describing how I am feeling about the whole Champix/emotions thing and that I was scared and thought maybe I should discontinue, when he turned his back and looked at his computer, I felt so let down and ignored - I just stormed out of the room.  I began thinking why am I with this guy??? I have been with this wonderful man 8 years, normally I can excuse the fact that he is not the most gifted with words because he is so amazing in every other way. He has a mild, sweet, quiet way about him - he also is taking Champix by the way (double trouble?). I don't know what the outcome will be (if I will continue Champix or not) but I sure hope it doesn't get any worse. Also experiencing nausea, gas, constipation and headaches.  Good luck to you guys!

  4. Michelle Michelle Canada says:

    The side effects got worse, I had a panic attack, first time ever.  Week 5 has been hell.  I am so depressed and angry.  I stopped taking Champix 2 days ago, still waiting for this to subside.  If you are considering taking Champix - think twice and if you do take it, keep a journal and keep track of your ups and downs.  I thought my family and fiancee would look out for me - guess what? That didn't happen. If you are on Champix and feel that you are acting out of character - GO TO YOUR DOCTOR!  This is dangerous stuff.

    • Paul Munneke Paul Munneke United Kingdom says:

      I was 5 weeks into taking Champix, and I completely lost the plot. I fell out with a lot of people and had to stop taking them. I was a time bomb waiting to explode, I used to smoke 15 a day now after taking Champix I smoke around 24, wished I never had taken them, worst experience of my life, think twice before taking them, I thought I could handle them but I was sadly mistaken, be very careful!

  5. Melissa Melissa Canada says:

    I was on champix for about a month and all was well. I had very little physical side effects that were mostly gastrointestinal (slight nausea/heart burn, decreased appetite). I sometimes felt groggy, which I chalked up to the occasional sleepless night. I did not experience depression or psychiatric symptoms. I had completely quit smoking by day 10 of using champix. Things were great...

    Then I had a seizure. It was a full-out 3.5 minute, tonic-clonic seizure. I bit my tongue in so many spots, it took a week to heal. I could barely walk for 2 days because my muscles were so sore.  My driver's license has been suspended. I'm having trouble getting time off work to make it to my Dr. appointments. I wasn't angry while on the drug, but I'm angry now!  I'm just lucky my friends were present at the time, if i had been alone I would have woken up with a "splitting headache" from what I would have figured was a "nap", and I would have continued taking a drug that could have potentially killed me.  

    There was no mention in the consumer leaflet that this drug could possibly cause seizures, I did, however, find this information in a nurses drug guide. But it was mentioned almost in passing. Also, it was too late.

    • sam sam United Kingdom says:

      Hi, my name is sam i am 36 years old. I have been told i have sleep epilepsy. There is no epilepsy in my family, i have never had a head injury, or had any illness that could of caused it. I was given champix in jan 08 they take two months to get into your system. I had my first fit in march of 08. I would not of even questioned a link to this tablet only, my freind who has had a head injury went to get the tablet off his doctor to give up smoking. His doctor refused and said it can cause seizures in people with head injury. So i asked my doctor when i had my tablet and thats what she said jan 08, can you see the link. The only differance i have found is that people who have had fits off the tablet, the fits have stoped when they stop the tablet, mine have not they seem to be getting worse. I have about 1 a month a moment. Always in my sleep, i have realy bad memory problems it has ruin my life.

  6. jeff jeff Canada says:

    I have been on Champix for four weeks and have had my first 10 cigarette or nicotine substitute free days in 24 years.  I had tried everything!!! Repeatedly.  Nothing has worked like this drug.  Thank God for it.  I feel like I'll never go back.  I know 3 other people in exactly the same boat as I am.  And frankly, not to pass judgement, but I would have signed up for just about any short term torture to get off these things.  They were going to kill me.  I knew it.  Yet I couldn't stop.  I have and I know I'll never smoke again.  I love you Pfizer.  I love you Champix.

  7. Michelle Michelle Canada says:

    I have been on for Champix for 7 weeks, stopped smoking day 10 and haven't had one since. I still get extreme nausea in the morning, but works better if I eat a slice of cheese, and space the AM and PM pills EXACTLY 12 hours apart. I have also gained 15 lbs, all in the first 2 weeks, hope it comes off!  However, about all the rest of the side effects I have read about, if you listen to the TV when they adevertise for ANY other drug, there is a long list of side effects as well, and they are still promoting these drugs.  So how come this is THE BAD ONE, what about all of the rest- you have to find something that works for you, because we all are different.

  8. Doreen Doreen Canada says:

    I am an almost 60 year old woman.  I have lost a 40 year old marriage, my mother and sister won't have anything to do with me anymore.  I have a quick temper which I never had Champix before.  I went into terrible depression after quitting Champix after almost 12 weeks on it. I asked the pharmacist if I should go off of it slowly like how I went on it.  He  said I was just to stop it not wean off it.  In 2 days I was a disaster of emotions and walked into my medical centre in tears saying someone had to help me.  I was told it couldn't be the Champix, but I have been on antidepressants ever since. I did quit smoking after 44 years,  but the rest of my life is not so good.

    • Liza Roux Liza Roux South Africa says:

      Hi Doreen

      I would like to know if you are better now in the year 2014. And if you have any advice for supporting someone that is going through the same thing?

  9. Kori Kori Canada says:

    I took champix for 5 weeks.  After 3 weeks I stopped taking the evening pill with hopes that I would sleep better and with less dreams - that did help a little.  Like many people I have been very short-tempered, bitter about things that I would not normally be upset about and generally difficult to live with (I feel bad for my kids and spouse).  All of this I could live with but I have started to become worried about twitching I have been getting in my left eye.  It started about 4 weeks ago and I thought that it was likely just because I have not been sleeping well and stressed about not smoking.  My eye probably twitches about 50 times a day.  Two days ago my left cheek twitched. I stopped taking the champix yesterday.  I'm not certain that this is a Champix side effect but it has scared me.  I have smoked, off and on, for 30 years but I feel confident that I won't start again - because I would never want to go through these  side effects again!  Good luck everyone.

    • dawn dawn Canada says:

      My boyfriend gets splitting headaches right after sex, has anybody expereinced this when taking Champix?

      • wendy swarts wendy swarts South Africa says:

        Has anyone been affected by flying cos i have been fine using champix and when got on a flight as soon as i was in the air i had a headache from hell and started vomiting once landed the headache only went away 4hrs later and now the next day its back any advice would be great

    • Kelsea Kelsea Canada says:

      I also experience a twitch which I have never had done before. The twitch usually happens 3 or more times a day. I twitch from my neck which makes my head turn left or right, lol. I am also very short tempered & I feel out of character a lot... Or I should say I feel like myself x 10. I'll be 10 times more everything like 10 times upset, depressed, happier, talkive, etc

  10. Mike Mike Canada says:

    I have a sister who took champix 3 yrs ago and before she took it ,she was the most passionate caring lovingI persone. She now has paranoia and suicidal thoughts. There is so much to tell from being handcuffed and taken to phycriatic ward , losing license, suicidal etc. I need to speak to a lawyer in Canada and hoping someone can help.
    I have lost the most loving person i love who thinks i am part of the powerful people out to get her.
    Thanks in advance

    • sam sam United Kingdom says:

      Hi Mike, sorry to hear about your sister, i was sectioned in feb 2011, she can get better, but you have to stop them giving her more drugs. I dont take any anti-depressants at all, and i got better, a psychotic episode, can right it self after about 40 days. Unless you are given drugs that keep it happening, as they act on your brain the same as champix does. Champix is classed as a pychotropic drug, its they same as the drug, they probably have her on now in hospital. They still act on same receptors in the brain.
      So if champix, made her ill, whats to say these drugs they have her on now ar,nt doing the same. Anyway Pfizer canada,
      have a obligation, they have it in writing, ring them and ask, this states that if anyone has side-effects from champix or chantix, that they have to keep in contact with that person untill side-effect has been resolved. Tell them Samantha Dearnaley in U.K, has a copy of it, and also i have been told this is true from the U.Ks Pfizer medical director Barkley Phillips that this is true. Also Erin Brocovich is helping by looking into chantix in USA, as you have differant laws to us in the Uk.

  11. Margaret Levesque Margaret Levesque Canada says:

    I have quit smoking using champix although my hearing loss excelerated quite quickly on it.I experienced buzzing and popping sounds while on champix can not say for sure it was the cause but i am now awaiting cochlear mplants .....anyone els have serious hearing loss on this drug

    • dayle dayle New Zealand says:

      yes - I took it for about 5 weeks then stopped. Although i stopped smoking in that time i had a really annoying buzzing noise every now and again - then i developed such sore muscles I could barely walk. It was at that point I stopped taking it and both the symptoms ( and the malaise and general fed up feelings) have gone. If I ever try quitting again it's going to have to be on my own - the champix experience was quite nasty - i also know of someone who ended up on antidepressants after taking it - so be very careful1

  12. Chris Chris Canada says:

    Hi - using champix for several weeks - thought to use it as just another smoking cessation tool rather than outright quitting after terrible headaches after two days on it despite taking two 500mg acetaminophen tablets as the instructions indicate to get something for the headaches. In reality i was down to just 2 - 3 cigarettes / day prior to quitting - the headaches got less severe after 4 days - headaches occur when you go without cigarettes and without champix anyways so i figured to get something other than acetaminophen after 5 weeks - i believe the trick is try to reduce your nicotine levels using nicotine gum - it requires getting adjusted to after the first few days as even the gum works differently than smoking - as long as i was on the gum i smoked occasionally however this causes asthma - i now realize i was short on breath after smoking. The point is even if you get down to just one cigarette per day if you quit you still must go several weeks without cigarettes until you are nicotine free - i now notice weight gain although i am not eating out of the ordinary - i still get very tired if i do not take champix if i miss just one dose - it is important to take champix after eating food and drinking water as it indicates in the instructions and i notice this helps to defeat the headaches although this will not work alone in the first four days in particular or thereafter for that matter from my past experience with acetaminophen - i recommend using ibuprofen rather than acetaminophen as it seems to work better to alleviate headaches after taking champix at this point - acetaminophen also makes you drowsy so i was taking it with caffeine in the morning immediately following taking champix expecting to get that headache one hour after taking it. The first five weeks i was smoking about one cigarette per day to immediately help with headaches although this is another huge mistake as this causes headaches in the long run - cigarettes are much stronger than nicotine gum. After five weeks of going on champix i finally decided to totally quit - two weeks with no cigarette + still addicted physically - if i miss one dose i still require nicotine or champix + ibuprofen. At this point i notice weight gain in the ten pounds or greater estimate - it is difficult to imagine how this stuff works for full time smokers who suddenly decide to quit.

    This is not the first time i quit smoking - i quit cold turkey four years ago when i was smoking six or seven cigarettes per day this is why i know it takes several weeks to rid of the addiction to nicotine - i guess i was not ready to quit. After going on champix for several weeks i never want to go through the headaches and additional expense of quitting again - this is my third time trying to seriously quit smoking - trying to quit smoking for years to get an idea what this requires. As another user wrote champix is your last resort - try to cut down using nicotine gum - if this causes your face to turn excessively red as it did with myself cut down semi gradually - it is very likely it is the cigarettes causing it as my face turned back to normal colour after outright quitting for several weeks four years ago - i cut down for one full year prior to finally deciding to quit - still addicted to nicotine without smoking or using nicotine gum for two full weeks to give you an idea - symptoms start to subside after three weeks of quitting cold turkey not using champix - i suspect this is still true while using champix in my current situation as i get less tired than several days ago - for sure be prepared for major headaches in the first four days after quitting - it also helps to space the doses no further than twelve hours apart during daylight hours - it causes dry mouth so try to take it earlier in the afternoon rather than late at night in order to get the proper rest - i was adding additional sugar to my diet to increase serotonin levels to help with the headaches that causes fatigue and depression - i discovered cinnamon capsules to level out the insulin response after increasing sugar intake - the government should reduce the effectiveness of nicotine out of cigarettes gradually to the point they are not addictive or there another problem of mass psychosis if cigarettes ever get banned by the government - i hope this was of help - good luck quitting.

  13. Chris Chris Canada says:

    Another thing is if you smoke occasionally while on champix for thee or four weeks when the headaches return after you require another cigarette or champix + ibuprofen the headaches get immediately more severe for three or four days so please try to cut down rather than prolong those damn headaches - thank you for reading.

  14. Jamie Mccombie Jamie Mccombie United Kingdom says:

    although i cannot prove it was the cause, i have at the age of 29 developed type1 diabetes after taking champix. Resulting in struggling to find work offshore now and lessening my chances of emigrating from the UK. I also get a strange twitching under my left eye that happens many times daily, stay clear of this drug please, try another way of stopping. I feel my ambitions have been ruined, dont let it ruin yours.

  15. Kristos Greek Kristos Greek Australia says:

    I used Champix for two weeks. I initally noticed that I was getting  an accetuated speed-trip, elation for a couple of hours followed by a chilled smooth few hours until something off the "downer". Then anger/impatience/anxiousness.

    So I stopped using Champix, researched some cold-turkey and have now been 10 days smoke free cold-turkey.

    The most alarming thing I believe about Champix wasn't the "trips"... te downers are the equivalent of speed. & days after I stopped I had withdrawal symtoms form the Champix- a very very dark depression for two days.

    I have experienced some pretty darktimes and am no stranger to depression, but being a generally happy and upbeat guy have never gotten to any treatment level of depression.

    But this was fast and very dark. It was so dark and so different to anything I have experienced that I almost immediately recognised it as an aberration and was able to write it off as chemically induced and manage it. For someone with no prior experience of such feelings or the ability to recognize that this not a natural down/depression I cans see how extremely dangerous this is.

    It is only 2 days since I experienced the depression I attribute to Champix and I am now being careful to see if there are any ongoing effects from 2 weeks on Champix. Let's hope not.

  16. Jabato CT Jabato CT Colombia says:

    Is Pfizer dulling the minds of politicians refusing to look at the increasing evidence? ONE LIFE OR ONE MIND LOST IS ONE TOO MANY!!!

    Enough is enough! We, the users constituting the experimenting testbed, have experienced first hand the effects of that hallucinogen. The manufacturer will always contend that there's not enough evidence $$$$$ People.... REACT!

  17. Yoplai Danon Yoplai Danon France says:

    In practice, Champix ® should be used by smokers who are motivated to stop smoking and enjoying further advice and monitoring. The patient should be taken one to two weeks before quitting. The initial dose is one tablet to 0.5mg per day for 3 days, followed by a 0.5 mg tablet twice daily during the following four days. Thereafter, the dosage is one 1 mg tablet twice daily until the end of treatment (12 weeks). The tablets should be swallowed whole with water. They can be taken with or without food

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News-Medical.Net.
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