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Champix (varenicline)

On this page

  1. About Champix
  2. Key facts
  3. Who can and cannot take Champix
  4. How and when to use Champix
  5. Side effects
  6. How to cope with side effects of Champix
  7. Pregnancy and breastfeeding
  8. Cautions with other medicines
  9. Common questions about Champix

1. About Champix

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.

2. Key facts

  • 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.

3. 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

4. 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:

Week 1:

  • 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?

Urgent advice: Contact 111 for advice now if:

  • you take too much Champix

Call 111 or go to 111.nhs.uk

If you need to go to A&E, 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.

5. Side effects

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)
  • headaches
  • 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.

Urgent advice: Tell your doctor now if you:

  • feel agitated, depressed or have thoughts about hurting yourself

Immediate action required: Call 999 now 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.

Immediate action required: Call 999 or go to A&E now if:
  • you get a skin rash that may include itchy, red, swollen, blistered or peeling skin
  • you're wheezing
  • you get tightness in the chest or throat
  • you have trouble breathing or talking
  • your mouth, face, lips, tongue or throat start swelling

You could be having a serious allergic reaction and may need immediate treatment in hospital.

These are not all the side effects of Champix. For a full list see the leaflet inside your medicine packet.

Information:

If you have other possible side effects, you can report them using the Yellow Card safety scheme.

Visit Yellow Card for further information.

6. 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.

7. 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.

Non-urgent advice: Tell your doctor if you're:

  • trying to get pregnant
  • pregnant
  • breastfeeding

8. 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.

Important

For safety, tell your doctor or pharmacist if you're taking any other medicines, including herbal medicines, vitamins or supplements.

9. Common questions about Champix

How does it work?

Champix helps people to stop smoking by copying the effect of nicotine in your body. This reduces the urge to smoke and helps with the withdrawal symptoms from nicotine such as:

  • the urge to smoke again
  • feeling depressed or irritable
  • difficulty sleeping

Most people who smoke would like to stop. One of the reasons that many struggle to stop is that nicotine, which you breathe in when you smoke, is addictive. Soon after your last smoke, you start to have withdrawal symptoms. This is where Champix can help.

However, Champix will not make you stop smoking on its own. You will still need to really want to succeed and break the smoking habit.

How long does it take to work?

You will slowly increase your dose of Champix dose during the first 8 days, to reduce your chances of feeling sick.

From day 9, you'll be able to notice that you crave fewer cigarettes each day. By that time, the amount of Champix in your body should be enough to help you stop smoking.

How long will I take it for?

Many people stop smoking within a 12-week course. However, sometimes your doctor may recommend an additional 12 weeks of treatment if:

  • you’ve stopped smoking but they think you need more time to prevent you from smoking again
  • you have not stopped smoking completely within the first 12 weeks – if you’re not ready or able to stop smoking straight away, try to cut back on your smoking during the first 12 weeks of treatment

If you have not stopped smoking after 24 weeks, talk to your doctor or nurse. They will be able to recommend other options, if this medicine is not working for you.

What will happen when I stop taking it?

A few people may get withdrawal effects for a short time if they stop taking Champix suddenly. You may have an urge to smoke again, feel depressed or irritable, and have difficulty sleeping.

To reduce the risk of these effects, your doctor may suggest that you gradually reduce the dose over a week or so, before you stop taking Champix.

It’s important to complete the full 12-week course, even if you have stopped smoking before the 12 weeks are up.

Are there other treatments that can help me stop smoking?

If you want to stop smoking, several stop smoking treatments are available from pharmacies, shops and on prescription.

The best treatment for you will depend on your personal preference, your age, if you're pregnant or breastfeeding and any medical conditions you have.

Other treatments include:

  • nicotine replacement therapy (NRT) a range of products which give a low level of nicotine, without the tar, carbon monoxide and other poisonous chemicals present in tobacco smoke. Available on prescription from a doctor or an NHS stop smoking service.
  • bupropion (Zyban) – a medicine originally used to treat depression, but it has since been found to help people stop smoking. Only available on prescription.
What NHS services are there to help me stop smoking?

Local stop smoking services are available to help you stop smoking. These free services provide support and effective methods to help you.

Your doctor can refer you, or you can phone a local stop smoking service to make an appointment with an adviser.

Find out more about NHS stop smoking services.

Can I drink alcohol with it?

Yes, you can drink alcohol with Champix. However, there have been some reports that taking Champix increases the effects of alcohol.

You may want to stop drinking alcohol or limit how much you drink while you're taking it.

Is there any food or drink I need to avoid?

You can eat and drink normally while taking Champix.

Will it affect my contraception?

Champix does not affect any type of contraception, including the combined pill and emergency contraception.

Will it affect my fertility?

There’s no clear evidence to suggest that Champix will reduce fertility in either men or women.

Can I drive or ride a bike?

Champix may sometimes make you feel sleepy or dizzy.

If this happens to you, do not drive a car, ride a bike, or use tools or machinery until you feel better.

Related conditions

Page last reviewed: 13 October 2020
Next review due: 13 October 2023