What is a Champix Tablet and how does it work?

Champix Stop Smoking Tablets

 What is Champix?

Champix is a drug that contains the active ingredient varenicline. It is available in tablet form (0.5 and 1 mg). Champix is used to help adults Quit smoking. The medication is only available with a prescription.

Champix treatment is more likely to be successful in smokers who are motivated to quit smoking and who are also receiving additional advice and support. Patients usually set a quit date for themselves and begin taking Champix one to two weeks before that date. Patients who are unwilling or unable to set a target date within one to two weeks of starting treatment may be offered treatment first and then choose a target date within five weeks of starting treatment.

Champix treatment lasts for 12 weeks. With water, the tablets are swallowed whole. The patient takes one 0.5-mg tablet once a day for three days in the first week, followed by one 0.5-mg tablet twice a day for four days. For the next 11 weeks, the patient will take one 1-mg tablet twice a day. Patients who do not tolerate the medication or who have kidney problems may be given lower doses.

Doctors may choose to continue treatment for another 12 weeks for patients who have successfully quit smoking after 12 weeks of treatment.

Smokers become addicted to nicotine, a chemical found in tobacco. Nicotine acts in the nervous system, where it binds to receptors and causes the release of dopamine, a chemical messenger that contributes to the pleasure derived from smoking.

Champix's active ingredient, varenicline, can bind to some of these receptors, known as the 42 nicotinic acetylcholine receptors. When varenicline binds to these receptors, it acts in two ways: it acts like nicotine (partial agonist), which helps to relieve craving symptoms, but it also acts against nicotine (antagonist), which helps to reduce the pleasurable effects of smoking.

In two large studies, 2,052 smokers were given a 12-week course of Champix, bupropion (another non-nicotine medication), or a placebo (a dummy treatment). The patients' target date for quitting was set at one week after starting treatment, and they were followed up on for the next 40 weeks to see if they started smoking again. The number of patients who had completely stopped smoking for four weeks (between weeks 9 and 12 of the study) was the primary measure of effectiveness, as confirmed by laboratory testing of the patients' breath for signs of smoking.