Quitting Medications

There are currently two medications available through your GP on prescription that can reduce withdrawal symptoms when you quit and greatly increase your likelihood of quitting.

  • Varenicline (used to be known as Champix – now in generic brand form from all  pharmacies)
  • Buproprion (also known as Zyban)

Research studies show that  Varenicline can more than double your chance of quitting, and Zyban nearly doubles your chance.

Medications will not stop all cravings entirely, but they will work on nicotine addiction. This makes it easier for you to focus on habits and routines; stress and smoking; and social situations and alcohol.

Talk to your doctor if you would like to use quitting medication to help you stop smoking.

The most effective way to quit is: counselling / behavioural support through a service such as Quitline  combined with  nicotine replacement therapy (NRT) or quitting medication (Varenicline/Zyban)


Varenicline works by reducing withdrawal symptoms and by reducing the satisfying effects of smoking. When you puff on a cigarette, nicotine travels through your lungs and into your bloodstream to your brain, where it attaches to receptors to release the brain-reward chemical, dopamine. Varenicline blocks these receptors and causes a release of a smaller but steadier amount of dopamine. NB: This medication was previously commonly known as Champix. It is now available as a generic brand from all pharmacies via a prescription from your GP.


Varenicline is a 12-week course. The advice is to continue to smoke in the first week and to set a quit date for some time in the second week. As the dose builds up, cigarettes will start to be less desirable and it will be easier to cut down before quitting in the second week. It’s important to take Varenicline for the full 12 weeks, even if you’re feeling quite confident that you have quit – Varenicline can help prevent relapse

Side Effects

Most people on Varenicline will have no side effects. The most common side effect is nausea, affecting about 3 out of 10 people. This may be eased by taking Varenicline with food, or your doctor may recommend reducing your dose. Nausea is usually mild to moderate and fades with time. Other potential side effects include having trouble sleeping and vivid dreams (in which case take the second tablet earlier in the day to see if this helps).

Less common side effects include stomach or bowel problems (e.g. constipation, gas, dry mouth, vomiting, indigestion), headache, dizziness, feeling tired, increased appetite and changes in taste. They are usually mild and they generally appear in the first week of taking the medicine. Talk to your doctor or pharmacist if you have any symptoms that concern you.

The risk of serious side effects is very low. These are listed in the pack insert. Some people have reported changes in mood or behaviour when taking Varenicline. If you have any symptoms you think could be serious, seek medical advice as soon as possible.

You cannot take Varenicline if you are under 18, pregnant, or breastfeeding. If you have a current mental health condition, consult your doctor before you start using any medications.

Zyban (Bupropion)

Zyban is an anti-craving medication to help people stop smoking, and is available on prescription. Using Zyban can help reduce withdrawal symptoms, such as cravings, irritability and difficulty concentrating, when you quit. Zyban may also make smoking seem less rewarding.


Zyban is a 9-week course. You slowly build up the dose in the first week. The advice is to continue to smoke in the first week of using Zyban and set a quit date for some time in the second week. It’s important to take Zyban for the full 9 weeks, even if you’re feeling quite confident, as even after regular cravings have faded, staying on Zyban can help prevent relapse.

Side Effects

Most people on Zyban will have no side effects. The most common side effects are difficulty sleeping, dry mouth, headache, dizziness, anxiety or nausea. To reduce sleeping problems, it’s best to take your second dose of the day at least four hours before bedtime (but you must leave eight hours between tablets). The most serious side effect is the risk of seizure, which is estimated to occur in about one in 1000 patients (0.1%). Your doctor will ask you a series of questions to determine if you are at risk from seizure. If you have a seizure, stop taking Zyban and seek medical attention immediately.