Taking Varenicline to Stop Smoking
Varenicline (brand name Champix®) is a medicine that helps you stop smoking. It works by partially blocking your nicotine receptors and so reducing cravings, withdrawal symptoms; and making smoking less enjoyable if you do smoke.
Who should not take varenicline
It cannot be prescribed to children and those with severe kidney disease. It can sometimes be prescribed for people with cardiovascular disease, severe psychiatric illness or a history of seizures. If any of these apply to you please check with your GP before starting the medication.
How to take varenicline
Ideally start the medication 2 weeks before your quit date but you can start up to 5 weeks before if this is delayed. This allows the medicine to build up in your body before stopping. Take the tablets as per the instructions on the box.
The dose schedule is:
- Days 1–3: 0.5 mg once daily
- Days 4–7: 0.5 mg twice daily
- From Day 8 onwards: 1 mg twice daily.
- Continue this dose for 12 weeks. Even if you successfully stop smoking during this period finish the whole course to help prevent a relapse.
- When stopping the medication abruptly, 3% of people can have withdrawal symptoms. These include irritability, an increased urge to smoke again or it can affect your mood. We recommend tapering the dose back down in the reverse to how you started it.
If you miss a dose, do not double up – just take your next dose at the usual time.
Possible side effects The most common side effects are nausea and headaches. Taking tablets after food usually helps. Rarely, varenicline can cause mood changes, low mood, or suicidal thoughts. Seek medical help immediately if you notice these. Further information can be found on the leaflet in the medication box.
