Varenicline (Champix or Chantix)

Varenicline (Champix or Chantix) is a molecule that aids smoking cessation by acting on the brain via nicotine receptors. The effectiveness of this treatment has been proven, but long-term cessation is often achieved through a variety of methods. In this section, you will read about how this medicine works as well as its main advantages and disadvantages.

How does it work?

Smokers develop a dependence on nicotine, a chemical product contained within tobacco. Nicotine acts on the nervous system, where it binds to receptors and triggers the release of a chemical messenger, dopamine, which plays a role in the pleasure felt when smoking. Varenicline can bind to some of these receptors - nicotine receptors and acetylcholine α4β2 (alpha4beta2). When it bonds with these receptors, varenicline acts in two ways: it acts like nicotine (partial agonist), which helps to relieve withdrawal symptoms, and it also acts against nicotine (antagonist) by taking its place, which allows it to decrease the pleasurable effects of smoking.

Advantages

Varenicline aids smoking cessation because it:

  1. Reduces withdrawal symptoms by acting on the nervous system in the place of nicotine
  2. Decreases the enjoyment of smoking by reducing the nervous system’s sensitivity to nicotine

Side effects

The most common side effects (observed in over 10% of patients) are nausea (desire to vomit), insomnia (trouble sleeping), abnormal dreams and headaches. For a complete description of the side effects observed in patients taking Champix®, please refer to the Consumer Medicine Informationliens_externe_bleu-sur-blanc. However, many of these secondary effects can be attributed to smoking cessation itself.

Swissmedic warns of the possible appearance or aggravation of psychiatric symptoms (modifications in behavior or thoughts, states of anxiety, psychoses, changes in mood, aggressive behavior, agitation, depression, suicidal thoughts or suicidal behavior). In the vast majority of cases these symptoms do not appear, but Swissmedic recommends that patients be supervised by a doctor when taking this medicine.

 

Warning from Swissmedic

It should be noted that the French agency for health products safety (AFSSAPSliens_externe_bleu-sur-blanc) has drawn up a list of medicines which require a drug monitoring investigation, and that varenicline features on this list because of suspected possible complications for psychiatric disorders, and a suspected suicide risk. The medicine is currently undergoing tests to establish the importance of these risks.

 

List of medicines requiring a drug monitoring investigation according to the AFSSAPS.(pdf)

Champix® must not be used by those who suffer from an allergy to varenicline or any of its other ingredients. In any case, only your doctor can prescribe this medicine. Make sure you tell him or her about any other medicines you are taking so that your prescription can be modified if necessary.

Pregnancy and Breastfeeding

There is not enough relevant data concerning the use of Champix® in pregnant women. Studies carried out on animals have highlighted toxic effects on foetal development and the presence of varenicline in breast milk. The potential clinical risk is not known. Champix® should not be used during pregnancy or breastfeeding except in extreme cases.

Summary

  • This medicine obtained the right to enter on the European Market in 2007. In Switzerland and France, Champix® has been available in pharmacies since 12 February 2007. In Belgium, it has been available since 4 December 2006.

  • Champix® is designed to help adults over 18 to quit smoking. The medicine can only be obtained on medical prescription.

  • Champix® should be used by smokers who are committed to quitting smoking. In addition, it is recommended that quitters receive professional support, medical advice and monitoring, as this considerably increases the chances of successful cessation.

  • The patient first sets a quit date.

  • The administration of Champix® begins 1 or 2 weeks before that date.

  • A box of Champix® contains two sorts of tablets. Tablets containing 0.5 mg varenicline are white; those containing 1.0 mg are light blue.

champix

  • The initial dosage consists of one 0.5 mg per day for 3 days, then one 0.5 mg tablet twice a day for the next four days. After that, the dosage is one 1 mg tablet twice a day until the end of the treatment (12 weeks).

  • The dosage can be reduced to 0.5 mg twice a day for patients who cannot tolerate a dosage of 1 mg twice a day. For patients with serious kidney problems, the dose of Champix® should be 1 mg once a day.

  • For patients who have succeeded in quitting smoking after 12 weeks, the doctor may recommend a complementary treatment lasting another 12 weeks. Alternatively, he or she may decide to stop the treatment gradually.

  • The tablets must be swallowed whole with water.

  • Tablets can be taken during or after meals.

     

    Summary of the dosage

    The information below is only intended as a guide. Your doctor must be the one to prescribe you this medicine and give you advice on how to take it.

    Day 1 - 3 of the treatment

    1 x 0.5 mg Champix® (white tablet)
    once a day

    Day 4 -7 of the treatment

    1 x 0.5 mg Champix® (white tablet)
    twice a day

    Your smoking quit date should fall between day 7 and day 15 of your treatment

     

    Week 2 – 12 of the treatment 1 x 1 mg Champix® (blue tablet)
    twice a day

     

    Price

    A full treatment, i.e. a 12 week supply, of varenicline costs around 600 Francs (7.15 Francs per day) in Switzerland and € 400 (€ 4.76 per day) in France. In Switzerland, this medicine is not included in basic medical insurance but may be covered by complementary insurance.

    We strongly advise against buying this product on the Internet because of the risk of counterfeiting and the absence of medical supervision. A medical opinion is very important for learning about contraindications, obtaining user instructions and advice on how to stop smoking, and to avoid or treat possible side effects.

    Effectiveness

    A recent meta-analysis (Cahill, Stead & Lancaster, 2009) comparing 9 trials with 7 267 participants in total, including 4 744 who used varenicline, showed that varenicline had a positive impact on smoking cessation. Champix® increases the chances of long-term cessation, and according to the authors of this analysis, the chances of successfully quitting smoking with varenicline are three times higher than without pharmaceutical treatment.

    "The pooled risk ratio (RR) for continuous abstinence at six months or longer for varenicline versus placebo was 2.33 (95% confidence interval [CI] 1.95 to 2.80)."

    The pooled risk ratio (RR) indicates that the chances of quitting smoking for six months or more are over twice as high with varenicline as with the placebo.

    On the other hand, the effectiveness of the molecule for preventing relapses has not been clearly demonstrated. Furthermore, the authors reveal possible links to serious side effects such as depression, agitation and suicidal thoughts. This is why it is essential to always be monitored by a doctor when following a course of Champix®.

    References

     

    Cochrane Review (meta-analysis)

    Selected studies

    See also

     

    Medication Forum
    Real life stories from people who have used varenicline

     

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    Documentation

    Stickers