Zyban (Bupropion)

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Medically reviewed by
Dr Daniel Atkinson
GP Clinical Lead
on August 02, 2022.
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What is Zyban?

Bupropion was originally marketed as an antidepressant, under the brand name Wellbutrin. One of the unintended side effects of Wellbutrin was that it seemed to reduce the desire to smoke for the people who took it. To the point that a lot of people who took Wellbutrin as an antidepressant ended up quitting smoking whether they wanted to or not.

Bupropion is now no longer used to treat depression. Instead it’s now only licensed to help people to quit smoking.

Zyban is a round, purple tablet with ‘ZYBAN 150’ imprinted on it. They come in a white, rectangular box, usually with 60 tablets inside. There will also be a blue and yellow Zyban logo on it, as well as the logo of its manufacturer.

The exact reason behind what makes Zyban effective at getting people to quit smoking is unknown. Experts believe that it alters some of the chemicals in the brain that are responsible for cravings and addiction.

One study, published in 2007, found that clinical concentrations of bupropion inhibit nicotine’s usual stimulatory effects on brain reward areas . This means that smoking no longer feels like a reward, helping to reduce its addictive qualities.

How to take Zyban to quit smoking

Once you’ve been prescribed Zyban by your doctor, you’ll be asked to set a date to quit smoking. You’ll usually be advised to set this date one to two weeks after starting your treatment so that your body can get used to it first.

Zyban is usually taken orally, with or without food. In most cases you’ll start with just one 150mg tablet per day for a total of six days. After this, patients will increase their dose to two tablets per day. These should be taken at least eight hours apart. The total course of treatment is around eight weeks.

Do not crush or chew your Zyban medication. This will release all of the medication at once and increase your risk of potentially harmful side effects. Instead, make sure that you swallow the tablet whole.

Timeline on how to use Zyban to stop smoking:

  • Day 1: start taking Zyban, once per day.
  • Day 7: increase dose to two tablets per day (spaced 8 hours apart). This step is age-dependent - if you’re 65 and over you’ll continue to take Zyban once a day from start to finish.
  • Day 7-14: stop smoking during this period, on a predetermined date.
  • Day 49-63: treatment finishes. You might be advised to stop taking Zyban gradually. If you haven’t stopped smoking after seven weeks of treatment you’ll probably be advised to stop taking Zyban.

If you miss a dose and it’s close to time for taking your next pill, skip the one that you missed. Never take a double dose as it could increase your risk of experiencing a seizure. It’s important that you follow the dosage instructions given to you by your doctor. You should also always read the patient information leaflet.

Coming off Zyban

Most people can stop Zyban abruptly. However, when coming off Zyban you’ll likely have a conversation with your clinician about how best to stop. You may be advised to gradually reduce your bupropion dosage, rather than stopping suddenly. This is because you can sometimes experience unpleasant withdrawal symptoms when you stop the treatment.

There are some circumstances where you should stop taking bupropion immediately – for example if you have a seizure. For more information about Zyban withdrawal, speak to your clinician.

How effective is Zyban?

Taking Zyban has been shown to increase the likelihood that you will be able to successfully quit smoking. Studies have shown that using bupropion doubled the rate of success in people trying to give up smoking, and compared with placebo or nicotine patch alone, people were more likely to have quit smoking after one year . Zyban is considered to be most effective when it’s used alongside a support service, like counselling or group support.

When does Zyban start working?

You should start to notice the effects of Zyban within two weeks of starting treatment, including a reduction in your cravings and desires to smoke. However if you don’t experience any difference in your cravings after three weeks of treatment, it may be that Zyban isn’t the right treatment for you. In this case, you should speak to your clinician to find out what your other stop smoking options might be.

Common side effects of Zyban

medically-reviewedAs with any medication, it’s normal to experience some side effects when you take Zyban. Some of the most common side effects can include:

  • dry mouth
  • difficulty sleeping
  • dizziness
  • drowsiness
  • nausea
  • constipation or diarrhoea
  • a strange taste in your mouth
  • sweating
  • stomach pain

A small number of people taking Zyban may experience raised blood pressure, severe headaches, muscle pain or vision changes. If you experience any of these, get in touch with your clinician straight away.

For more information about the side effects of Zyban, take a look at our comprehensive guide.

Although Zyban can be used effectively to help many people stop smoking, there are also some people who shouldn’t take Zyban. Don’t take Zyban if you:

  • are under the age of 18
  • are pregnant or breastfeeding
  • have ever had epilepsy, a seizure or an unexplained blackout
  • have ever suffered from anorexia or bulimia
  • have been diagnosed with bipolar affective disorder
  • drink heavily, or are withdrawing from alcohol dependence or benzodiazepines
  • have a tumour of the brain or spinal cord
  • have previously suffered an allergic reaction to bupropion tablets

You may find that your dosage of bupropion needs to be reduced if you:

  • have diabetes that is treated with insulin or medicine
  • drink excessive amounts of alcohol
  • have ever had a serious head injury
  • have liver or kidney disease

Before prescribing Zyban, your clinician will also want to know if you’re currently taking any medications, and what these are, as some medicines aren’t compatible with Zyban.

As with any medication, you should make sure that you only take the dose stated by your clinician, as overdosing on Zyban can be very dangerous. Taking more than the stated dose, or taking your doses too close together, can increase the risk of you having a seizure. If you’ve taken too much Zyban then you should seek medical help straight away.

Like any other antidepressant, it isn’t advisable to drink alcohol while taking bupropion (Zyban). This is because it can increase your risk of experiencing unpleasant side effects. It’s also been suggested that bupropion can reduce your alcohol-tolerance levels, which can increase your risk of alcohol poisoning.

Some of the side effects that are more likely to occur if you drink alcohol while taking Zyban include increased dizziness, confusion, loss of coordination and low mood.

If you drink heavily, it might not be safe for you to take Zyban. It might also not be safe for you to stop drinking suddenly so that you can start taking Zyban, so it’s important to be honest with your clinician about your health when you’re considering taking treatments to help you stop smoking. They’ll be able to advise you on the best and safest smoking cessation treatments for you.

Although many smoking cessation treatments, like nicotine replacement therapies (NRTs), can be purchased over the counter, Zyban (bupropion) is only available on prescription. This is so your clinician can make sure that it’s safe and suitable for you to use it.

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This page was medically reviewed by Dr Daniel Atkinson, GP Clinical Lead on August 02, 2022. Next review due on August 01, 2024.

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