Champix tablets contain the active ingredient varenicline, which is a medicine used to help people who are addicted to nicotine to give up smoking. It acts in the brain, but is not the same as nicotine replacement therapy.
Varenicline is a type of medicine called a nicotinic acetylcholine receptor partial agonist. This means that it acts on the same receptors in the brain as nicotine does.
Varenicline works by stimulating the nicotinic receptors in the brain. This produces an effect that relieves the craving and withdrawal symptoms you can get when you stop smoking. At the same time, varenicline blocks nicotine from acting on the receptors. This prevents any nicotine inhaled in tobacco smoke from having a rewarding and enjoyable effect. However, it is recommended that you don’t smoke while you are taking this medicine.
You should seek help and support as much as possible while giving up smoking, even while taking this medicine, as this will increase your chance of success. Your doctor, practice nurse or local pharmacist can all provide this support.
You should start taking this medicine while you are still smoking and set a 'target stop date' for within the first two weeks of treatment. This is because the medicine needs time to start working.
The dose is increased gradually in the first week of treatment and the medicine is then taken twice a day for 12 weeks. If you have successfully managed to stop smoking at the end of 12 weeks, your doctor may offer you a further 12 week course of treatment.
The tablets should be swallowed whole with a drink of water. They can be taken with or without food.
What is it used for?
Aid for giving up smoking.
Warning!
This medicine might make you feel dizzy or sleepy and so could impair your ability to perform potentially hazardous tasks such as driving or operating machinery. You should avoid driving or operating machinery until you know how this medicine affects you and are sure that it won’t affect your ability to perform such activities safely.
Some people may find that when they stop taking this medicine their urge to smoke returns. They may also feel irritable, depressed or have difficulty sleeping. To avoid this, your doctor may consider reducing your dose slowly when you finish treatment with this medicine, rather than stopping it abruptly. Discuss this with your doctor.
Use with caution in
Decreased kidney function
History of psychiatric illness, eg depression
Epilepsy.
Not to be used in
Pregnancy.
This medicine is not recommended for children and adolescents under 18 years of age, as there is no information regarding its safety and efficacy in this age group.
This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.
Pregnancy and Breastfeeding
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
The safety of this medicine for use during pregnancy has not been established. It should not be used by pregnant women. Seek further medical advice from your doctor.
It is not known if this medicine passes into breast milk, but it is possible that it may. As a result, it is not recommended for mothers who are breastfeeding. If you have been unable to give up smoking using any other method, you should discuss with your doctor whether it may be appropriate to stop breastfeeding in order to try this medicine. This will depend on factors such as the importance of breastfeeding to the child, how much smoke the child is being exposed to and how likely this medicine is to help you stop smoking. Seek medical advice from your doctor.
Side effects
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
Nausea
Headache
Difficulty sleeping (insomnia)
Abnormal dreams
Sleepiness
Dizziness
Change in taste
Dry mouth
Disturbances of the gut such as constipation, diarrhoea, vomiting, abdominal discomfort, indigestion, flatulence
Changes in appetite
Airway infections
Mood swings
Changes in sex drive
Tremor
Restlessness
Awareness of your heart beat (palpitations)
Skin reactions such as rash or itching
Increased urination
Chest pain
Increased blood pressure
The side effects listed above may not include all of the side effects reported by the drug's manufacturer.
For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
How can this medicine affect other medicines?
It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to ensure that the combination is safe.
The components of tobacco smoke can cause certain medicines, for example those listed below, to be removed from the body faster than normal. When you stop smoking, they are removed slower, so their blood levels may increase. This means that doses of these medicines may need adjusting after you stop smoking:
clozapine
dextropropoxyphene
flecainide
fluvoxamine
olanzapine
pentazocine
phenylbutazone
some benzodiazepines, eg oxazepam
some beta-blockers, eg propranolol
tacrine
theophylline
tricyclic antidepressants, such as imipramine
warfarin.
People with diabetes who smoke normally need more insulin, as smoking reduces the amount of insulin that is absorbed into the blood from an injection under the skin. If you have diabetes and are giving up smoking, you may subsequently need a reduction in your insulin dose. Discuss this with your doctor.
The safety and benefits of taking this medicine in combination with other medicines for stopping smoking have not been studied. Other smoking cessation medicines are therefore not recommended while you are taking this one. Using nicotine replacement therapy (NRT) in combination with this medicine has been shown to increase nausea, headache, vomiting, dizziness, indigestion, fatigue and a drop in blood pressure compared to NRT alone.
If you have severe kidney problems you should not take cimetidine in combination with this medicine, as it may increase the amount of varenicline in the blood.
Other medicines containing the same active ingredient
There are currently no other medicines available in the UK that contain varenicline as the active ingredient.
