This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
Some anti-smoking medicines are designed specifically to reduce cravings for the nicotine in cigarettes. They include the drug varenicline and nicotine replacement therapy (NRT), such as patches and gum. But medicines designed to treat depression may also help people to stop smoking. One antidepressant, called bupropion, can be prescribed as an anti-smoking medicine in the UK.
This comprehensive Cochrane systematic review looks at the available evidence for how helpful and safe different antidepressants are when used to quit smoking.
The results provide strong evidence that bupropion is an effective treatment for helping people to quit smoking. However, people who use bupropion are more likely to experience side effects (including mental health problems) and stop taking the medication than people who take a placebo (a ‘dummy’ tablet). The review found that bupropion may be as effective as NRT, but is less effective than varenicline at helping people to quit smoking. It concludes that varenicline may be a more suitable treatment for people who want to quit smoking and especially for those with mental health issues.
In the UK, bupropion is rarely prescribed as a stop smoking treatment although it is an option in the current guidelines. The results of this study support current practice.
What’s the issue?
Tobacco smoking is one of the world’s biggest public health problems. It is a leading cause of early deaths, with more than six million people dying yearly due to tobacco use. Smoking rates are falling in most countries around the world. Even so, in England, one in seven adults (14.4%) still smoke and there are 77,800 smoking-related deaths each year, representing more than one in six of all deaths.
Local NHS stop smoking services help improve a person’s chances of permanently quitting. They provide accurate information, advice and support during the first few months of stopping smoking. They also make it easy and affordable to obtain medications including varenicline, NRT, and the antidepressant, bupropion. In New Zealand, the antidepressant nortriptyline is also sometimes used.
What’s new?
This study reviewed the current evidence on whether antidepressants help people to stop smoking. It also looked at the safety of these medicines. It included 115 studies, and built on a previous review published in 2014.
The researchers looked at how many people quit for six months or longer when taking a treatment or a placebo. They looked at the side effects of different treatments as well as how many people stopped taking their medication.
They found that:
- using bupropion makes it 52% to 77% more likely that a person will successfully stop smoking for six months or more (equal to five to seven more people successfully quitting for every 100 who attempt to quit)
- nortriptyline also improves the chances of success
- bupropion increases unwanted side effects, particularly those relating to mental health (such as anxiety and insomnia), which increases the chance that people will stop taking the medication
- people taking bupropion are as likely to quit smoking as those using nortriptyline or NRT
- people using varenicline are more likely to quit smoking than those using bupropion.
The researchers found no clear evidence that taking bupropion at the same time as other stop smoking treatments, like varenicline or NRT, increases the likelihood of success.
Why is this important?
In the UK, current NICE guidelines (2018) recommend the use of bupropion, NRT, or varenicline to help adults quit smoking. However, the guidelines state that the most effective approach is likely to be either varenicline and behavioural support, or a combination of short- and long-acting NRT. In practice, NHS stop smoking services rarely prescribe bupropion. The results from this study support current practice.
What’s next?
There is strong evidence to show that bupropion is an effective treatment for helping adults to quit smoking for six months or longer. Further research is unlikely to change this conclusion.
More studies are needed to address other questions, such as the risk of serious side effects when using bupropion, and to clarify the most effective dosing strategy. The effectiveness of bupropion when combined with varenicline or NRT also needs further study. As bupropion is an antidepressant, it would also be useful to look further at whether people with past or current depression are more likely to quit smoking when using it, especially considering that there may be an increased risk of mental health side effects.
You may be interested to read
The full paper: Howe S, and others. Antidepressants for Smoking Cessation. Cochrane Database Syst Rev. 2020;4: CD000031
NICE guideline [NG92]: Stop smoking interventions and services (2018)
Hartmann-Boyce J, and others. Nicotine replacement therapy versus control for smoking cessation. Cochrane Database Syst Rev. 2018;5: CD000146.
Lindson N, and others. Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation. Cochrane Database Syst Rev. 2019;4: CD013308.
Funding: This research was supported by NIHR infrastructure funding for Cochrane Tobacco Addiction.
Conflicts of Interest: The study authors declare no conflict of interest. Peter Hajek, who provided the comment, has received fees and research funding from pharmaceutical companies which produce anti-smoking treatments.
Disclaimer: Summaries on NIHR Evidence are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that the views expressed are those of the author(s) and reviewer(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.
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