Bupropion (Zyban)

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.

Research results

Researchers from the Cochrane Collaboration and the U.S. Agency for Healthcare Research and Quality (AHRQ) systematically analyzed studies on this drug. They found that bupropion helps about 6 out of 100 people to successfully quit smoking.

One large study also looked into whether taking 300 mg bupropion per day is more effective than taking 150 mg bupropion per day. The two doses were found to be equally effective.

The possible side effects of bupropion include sleep problems, mouth dryness and nausea. About 12 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.

Bupropion can somewhat limit potential weight gain caused by quitting smoking – but only during the treatment. People who took it for 6 to 12 months gained about one kilogram less than those who took a placebo (fake drug). Several months later there was no longer any difference.

The researchers also analyzed studies on other antidepressants and the herbal medicine St. John’s wort. But these medications weren’t found to help people quit smoking.

Varenicline (EU: Champix, U.S.: Chantix)

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: On the one hand it relieves nicotine withdrawal symptoms; on the other, it makes smoking less pleasurable.

Treatment with varenicline is also started before people 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. People also stop smoking in 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.

It can make you feel sleepy, affecting your ability to drive. So it’s a good idea to stop driving or operating machinery until you know how you react to the medication.

Research results

Varenicline is currently thought to be the most effective medication for quitting smoking. Studies show that it helps about 12 out of 100 people to stop smoking tobacco.

Varenicline caused nausea in about 20 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 a half (two 0.5 mg tablets per day). If someone has advanced kidney failure, they shouldn’t take more than 1 mg per day.

Varenicline doesn’t appear to have an effect on people’s weight.

Sources

• Cahill K, Lindson-Hawley N, Thomas KH, Fanshawe TR, Lancaster T. Nicotine receptor partial agonists for smoking cessation. Cochrane Database Syst Rev 2016; (5): CD006103. [PMC free article: PMC6464943] [PubMed: 27158893]
• Hughes JR, Stead LF, Hartmann-Boyce J, Cahill K, Lancaster T. Antidepressants for smoking cessation. Cochrane Database Syst Rev 2014; (1): CD000031. [PMC free article: PMC7027688] [PubMed: 24402784]
• Patnode CD, Henderson JT, Thompson JH, Senger CA, Fortmann SP, Whitlock EP. Behavioral Counseling and Pharmacotherapy Interventions for Tobacco Cessation in Adults, Including Pregnant Women: A Review of Reviews for the U.S. Preventive Services Task Force. September 2015. (AHRQ Evidence Syntheses; Volume 134).
• Sterling LH, Windle SB, Filion KB, Touma L, Eisenberg MJ. 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, Higgins JP, Gunnell D. 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. We do not offer individual consultations.

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