Zyban tablets contain the active ingredient bupropion hydrochloride, 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.
It is not fully understood how this medicine works to help people give up smoking, but it is known that bupropion affects neurotransmitters in the brain. Neurotransmitters are chemicals that are stored in nerve cells and are released from nerve cells as a message is transmitted from one to the other. Once the message has been transmitted, the nerve cells then reabsorb the neurotransmitter.
Bupropion prevents two of these neurotransmitters, noradrenaline and dopamine, from being reabsorbed back into the nerve cells in the brain. Noradrenaline and dopamine are responsible for moderating mood and various other processes in the brain.
It is thought that bupropion helps people to quit smoking by increasing the amount of noradrenaline and dopamine free to act in the brain, thereby limiting the effect that stopping smoking has on the mood.
Bupropion is used in combination with motivational support techniques. 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.
You should start taking Zyban whilst you are still smoking.
Set yourself a target date to stop smoking during the second week of taking Zyban.
Follow the dosage regimen below:
- Days 1 to 6 – take one 150mg once a day
- Days 7 to 14 – take one 150mg tablet twice a day, 8 hours apart but not near to bedtime
- Day 15 onwards for 7 weeks – carry on with 150mg twice a day as above.
Take the Zyban tablets with water and swallow them whole. Do not crush or split them as this could result in the active ingredient being released too quickly and increase the likelihood of side effects.
You can take Zyban with or without food.
It is best not to stop taking the Zyban immediately. You should reduce the dose gradually over 10 to 14 days. This should be discussed with your doctor or pharmacist.
Medicines and their possible side effects can affect individual people in different ways. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect. The following are some of the side effects that are known to be associated with Zyban:
Very common (affect more than 1 in 10 people):
- Difficulty sleeping (insomnia). Avoid taking a dose of this medicine at bedtime.
Common (affect between 1 in 10 and 1 in 100 people):
- Concentration disturbance.
- Anxiety and agitation.
- Taste disturbances.
- Dry mouth.
- Disturbances of the gut such as constipation, nausea, vomiting or abdominal pain.
- Fever (high temperature).
- Rash or itching.
- Allergic skin rashes such as hives.
Uncommon (affect between 1 in 100 and 1 in 1000 people):
- Loss of appetite.
- Visual disturbances.
- Sensation of ringing or other noise in the ears (tinnitus).
- Increased blood pressure (see warning section above).
- Increased heart rate (tachycardia).
- Chest pain.
- Feeling weak.
The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.
For more information about any other possible risks associated with Zyban, please read the information provided with the medicine or consult your doctor or pharmacist.
Some people feel depressed when they give up smoking and some of these people experience thoughts of suicide or harming themselves. These experiences have also been reported in some people taking Zyban to help them give up smoking. If you notice any changes in your mood or behaviour, feel depressed or have any thoughts about suicide or harming yourself during treatment with this medicine, you should consult your doctor immediately.
Zyban may reduce your ability to drive or operate machinery safely. Do not drive or operate machinery until you know how this medicine affects you and you are sure it won't affect your performance.
You should minimise how much alcohol you drink or avoid drinking it entirely while you are taking Zyban. This is because some people find they become more sensitive to alcohol while they are taking it. If you do drink a lot at the moment don't just stop suddenly, because this could put you at risk of having a fit.
Your blood pressure should be monitored while you are taking this medicine because it can sometimes cause blood pressure to increase.
If Zyban is used in combination with nicotine replacement this has been shown to have a higher risk of increasing your blood pressure. Consult your doctor before using nicotine replacement therapy, such as nicotine patches or gum, in combination with this medicine. If your doctor says you can use nicotine replacement therapy while you are taking Zyban, your blood pressure should be monitored every week.
This medicine can cause a false-positive result in some urine drug tests for amphetamines. If you require a urine test, tell your doctor or hospital that you are taking Zyban.
Zyban should be used with caution in:
- Elderly people.
- People with decreased kidney or liver function.
- People who regularly drink large amounts of alcohol.
- People who have had a head injury.
- People taking medicines known to increase the risk of seizures.
- People with diabetes treated with insulin or other medicines.
- People with high blood pressure (hypertension).
- People with a history of psychiatric illness.
Zyban should NOT be used in:
- People with a history of fits (seizures) or disorders that cause fits, e.g. brain injury or epilepsy.
- People with a tumour in the brain or spinal cord (central nervous system).
- People who are going through abrupt withdrawal from alcohol or any drug or medicine for which there is a risk of seizures during withdrawal, for example benzodiazepines such as diazepam or temazepam.
- People with anorexia nervosa or a history of this.
- People with bulimia nervosa or a history of this.
- People with a history of bipolar disorder (manic depression).
- People with severe cirrhosis of the liver.
- People who have taken a type of medicine called a monoamine-oxidase inhibitor (MAOI) for depression or Parkinson's disease in the last 14 days.
- People taking any other medicinal product that contains bupropion.
- This medicine is not recommended for children and adolescents under 18 years of age, as the manufacturer has not studied its safety and effectiveness 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 Zyban and inform your doctor or pharmacist immediately.
The patient information leaflet (PIL) is a leaflet containing specific information about medical conditions, doses and side effects. You can download a copy of the PIL here:
Patient Info Leaflet