How is bupropion (Zyban) used?

The drug bupropion was originally developed for the treatment of depression. Because it was also found to help relieve nicotine withdrawal symptoms, it was approved as an aid to quit smoking, under the trade name “Zyban.” It is taken once or twice a day in the form of a tablet, and doesn’t have to be taken with meals. One tablet contains 150 mg of bupropion.

You start the treatment before trying to quit smoking: The first tablet is taken 1 to 2 weeks before the day on which you want to quit. You then carry on taking the tablets for seven weeks. The total cost of one round of treatment with Zyban is about 150 euros. The exact cost will depend on what dose you use, for example.

How effective is bupropion?

Researchers from the Cochrane Collaboration systematically analyzed studies on the use of bupropion to quit smoking. The results show that bupropion helps about 7 out of 100 people to successfully quit smoking.

Some studies looked into whether taking 300 mg of bupropion per day is more effective than taking 150 mg of bupropion per day. They showed that the higher dose didn’t have any benefit.

What side effects does bupropion have?

The possible side effects of bupropion include sleep problems, mouth dryness and nausea. About 9 out of 100 participants experienced sleep problems. Mouth dryness and nausea were less common. There is also a very small risk of serious side effects such as seizures. These side effects occurred in considerably less than 1 out of 100 participants.

How is varenicline (EU: Champix, U.S.: Chantix) used?

Another medication that’s available for people who would like to quit smoking is called varenicline (trade name: Champix in the EU, Chantix in the U.S.). It has two effects:

• It relieves nicotine withdrawal symptoms, and
• it makes smoking less pleasurable.

Treatment with varenicline is also started one to two weeks before you try to quit smoking. The dose is then gradually increased. You take:

• one 0.5 mg tablet per day on the first 3 days of treatment,
• two 0.5 mg tablets per day on days 4 to 7 of treatment, and
• two 1 mg tablets per day from the second week of treatment onwards. You also stop smoking during the second week of treatment.

Varenicline tablets are taken in the morning and evening with a glass of water, not necessarily with meals. The treatment lasts twelve weeks in total.

How effective is varenicline?

Varenicline can effectively help you quit smoking. Studies show that it helps about 13 out of 100 people to stop smoking tobacco.

What side effects does varenicline have?

Varenicline caused nausea in about 19 out of 100 people in the studies. But the nausea was often only mild and went away again during the course of the treatment. About 5 out of 100 people had sleep problems and/or strange dreams.

The aim of gradually increasing the dose at the beginning of the treatment is to prevent side effects like nausea. People who still don’t tolerate varenicline well can reduce the dose by half (two 0.5 mg tablets per day). If you has advanced kidney failure, you shouldn’t take more than 1 mg per day.

Are other medications available?

The drug cytisine is also approved for use in quitting smoking. It increases the likelihood of successfully quitting as well. There are fewer studies on cytisine than there are on the other approved medications, though.

Some other medications, including some antidepressants and plant-based medicines made from St. John’s wort, are also considered as treatments for quitting smoking. But they are not well studied for this purpose. Studies done so far don’t show that they can help.

Sources

• Batra A, Kiefer F, Andreas S et al. S3-Leitlinie „Rauchen und Tabakabhängigkeit: Screening, Diagnostik und Behandlung“. AWMF-Registernr.: 076-006. 2021.
• Benowitz NL, Pipe A, West R et al. Cardiovascular Safety of Varenicline, Bupropion, and Nicotine Patch in Smokers: A Randomized Clinical Trial. JAMA Intern Med 2018; 178(5): 622-631. [PMC free article: PMC6145797] [PubMed: 29630702]
• Cahill K, Lindson-Hawley N, Thomas KH et al. Nicotine receptor partial agonists for smoking cessation. Cochrane Database Syst Rev 2016; (5): CD006103. [PMC free article: PMC6464943] [PubMed: 27158893]
• Howes S, Hartmann-Boyce J, Livingstone-Banks J et al. Antidepressants for smoking cessation. Cochrane Database Syst Rev 2020; (4): CD000031. [PMC free article: PMC7175455] [PubMed: 32319681]
• Sterling LH, Windle SB, Filion KB et al. Varenicline and Adverse Cardiovascular Events: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Am Heart Assoc 2016; 5(2): e002849. [PMC free article: PMC4802486] [PubMed: 26903004]
• Thomas KH, Martin RM, Knipe DW et al. Risk of neuropsychiatric adverse events associated with varenicline: systematic review and meta-analysis. BMJ 2015; 350: h1109. [PMC free article: PMC4357491] [PubMed: 25767129]

• IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

  Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. informedhealth.org can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

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