Champix (also called varenicline) is a medicine that can help you stop smoking.
It reduces the cravings for nicotine and helps with the withdrawal symptoms you get when you stop smoking. These can include an urge to smoke again, feeling depressed or irritable, and difficulty sleeping.
Champix is only available on prescription and comes as tablets.
- Champix will not make you stop smoking on its own. You will still need determination to break the smoking habit.
- The usual course of treatment lasts 12 weeks.
- After 9 days of taking Champix, you'll be able to notice that you crave fewer cigarettes each day. The amount of Champix in your body should be enough to help you stop smoking.
- Common side effects include headaches, feeling sick or dizzy.
- It’s important to decide on a date you want to stop smoking. You’ll start taking Champix 1 week before this date.
Who can and cannot take Champix
Champix can only be taken by adults aged 18 years and over.
Tell your doctor before starting Champix if you:
- have ever had an allergic reaction to Champix or any other medicine
- have kidney problems
- have a mental health condition
- have problems with your heart
- are pregnant or breastfeeding
How and when to use Champix
Always take this medicine exactly as your doctor has told you. Check with your doctor or pharmacist if you are not sure.
It’s important to decide on the date you want to stop smoking. You’ll start taking the tablets 1 week before your stop smoking date. This allows you to build up the dose and gradually helps your body get used to the medicine.
Champix tablets can be taken with or without food. If you find taking Champix makes you feel sick, try taking it after a meal or snack.
Swallow the tablet whole with a drink of water.
Dosage and strength
Champix tablets come as 0.5mg and 1mg tablets.
A course of treatment usually lasts for 12 weeks.
Your weekly plan may be:
- day 1 to 3 – one 0.5mg tablet taken once a day
- days 4 to 7 – one 0.5mg tablet taken twice a day, once in the morning and once in the evening
Weeks 2 to 12:
- day 8 to end of treatment – one 1mg tablet taken twice a day, once in the morning and once in the evening
It’s important to complete the full 12-week course, even if you have stopped smoking. Completing the course will help you not start smoking again.
Your doctor may recommend taking Champix for a further 12 weeks, if they think it will reduce your risk of starting smoking again.
What if I forget to take it?
If you forget a dose, take it as soon as you remember unless it's less than 3 hours before your next dose is due. In this case it's better to leave out the missed dose and take your next dose as normal.
Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.
If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.
What if I take too much?
Call your local emergency service if:
- you take too much Champix
If you need to go to an emergency unit, do not drive yourself. Get someone else to drive you or call for an ambulance.
Take the Champix box, or the leaflet inside it, plus any remaining medicine with you.
Like all medicines, Champix can cause side effects, although not everyone gets them.
Common side effects
These common side effects may happen in more than 1 in 100 people. They're usually mild and go away by themselves.
Keep taking the medicine but talk to your doctor if these side effects bother you or do not go away:
- sore or swollen (inflamed) nose and throat
- feeling sick (nausea)
- difficulty sleeping
- feeling dizzy
- bad taste in your mouth
Serious side effects
Serious side effects are rare and happen in less than 1 in 10,000 people.
Tell your doctor now if you:
- feel agitated, depressed or have thoughts about hurting yourself
Call your local emergency service if:
- you have had a seizure or fit
- you get weakness on one side of your body, trouble speaking or thinking, loss of balance or blurred eyesight – these can be signs of a stroke
- you get chest pain or shortness of breath – these may be signs of a heart attack
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to Champix.
These are not all the side effects of Champix. For a full list see the leaflet inside your medicine packet.
How to cope with side effects of Champix
What to do about:
- sore or swollen (inflamed) nose and throat – talk to your doctor if these side effects bother you or do not go away. You could also try taking an anti-inflammatory medicine like ibuprofen for a few days.
- feeling sick – stick to simple meals and do not eat rich or spicy food. It might help to take your Champix after a meal or snack.
- headaches – make sure you rest and drink plenty of fluids. Do not drink too much alcohol. You can take an everyday painkiller like paracetamol. Talk to your doctor if the headaches last longer than a week or are severe.
- feeling dizzy – as your body gets used to Champix, this side effect should wear off. If you feel dizzy, sit or lie down until you feel better. Do not drive, cycle or operate machinery until you feel OK again. Try to avoid alcohol as it will make you feel worse.
- difficulty sleeping – try taking your last dose earlier in the evening and not too close to bedtime.
- bad taste in your mouth – try chewing sugar-free gum. You could also rinse your mouth with water or have a drink of juice or water.
Pregnancy and breastfeeding
Champix and pregnancy
Champix is not usually recommended if you’re pregnant. This is because there’s not enough evidence to know whether it’s safe for your baby.
Smoking during pregnancy increases the risk of miscarriage, some birth defects, premature birth, low birth weight, and some pregnancy complications.
Your doctor may be able to recommend a different option to Champix, such as nicotine replacement therapy (NRT).
Champix and breastfeeding
There is not enough research to know whether Champix gets into your breast milk. You're generally recommended not to take this medicine if you're breastfeeding.
Cautions with other medicines
Champix does not usually have an effect on any other medicines.
However, when you stop smoking, with or without Champix, your doctor may need to change your dose of medicines such as:
- theophylline, a medicine for breathing problems
- warfarin, a medicine to reduce blood clotting
- insulin, to treat diabetes
- olanzapine and clozapine, used to treat psychosis
Mixing Champix with herbal remedies or supplements
There's very little information about taking herbal remedies and supplements while taking Champix. They’re not tested in the same way as medicines. Ask a pharmacist for advice.