In this blog for people wanting to quit smoking, Sarah Chapman shares new Cochrane evidenceCochrane Reviews are systematic reviews. In systematic reviews we search for and summarize studies that answer a specific research question (e.g. is paracetamol effective and safe for treating back pain?). The studies are identified, assessed, and summarized by using a systematic and predefined approach. They inform recommendations for healthcare and research. on the effectivenessThe ability of an intervention (for example a drug, surgery, or exercise) to produce a desired effect, such as reduce symptoms. of nicotine replacement therapy.

People who use a combination of nicotine replacement therapies (NRT) are more likely to successfully quit smoking than those using one type. That’s the headline message backed by high quality evidence, in the new Cochrane Review published today.

This is a really important finding both for people buying nicotine replacement products to help them quit and for those commissioning NHS stop smoking services.

What is nicotine replacement therapy (NRT)?

 We already have evidence that nicotine replacement therapy can help smokers to quit. It does this by replacing the nicotine they are used to getting from tobacco, getting it to the brain through a variety of routes. NRT is available as sprays (into the nose or mouth), inhalers, gum, lozenges, tablets and skin patches. But which way is best?

New evidence about NRT

A team from Cochrane Tobacco Addiction did a systematic reviewIn systematic reviews we search for and summarize studies that answer a specific research question (e.g. is paracetamol effective and safe for treating back pain?). The studies are identified, assessed, and summarized by using a systematic and predefined approach. They inform recommendations for healthcare and research. with the aim of answering this question. They looked for all the relevant researchThe term research means different things to different people, but is essentially about finding out new knowledge that could lead to changes to treatments, policies or care. studies and found 63 trialsClinical trials are research studies involving people who use healthcare services. They often compare a new or different treatment with the best treatment currently available. This is to test whether the new or different treatment is safe, effective and any better than what is currently used. No matter how promising a new treatment may appear during tests in a laboratory, it must go through clinical trials before its benefits and risks can really be known. involving 41,509 smokers (mostly adults) who wanted to quit. Most smoked at least 15 cigarettes a day at the start.

More is better

They found that people using a nicotine patch together with another type of NRT, such as lozenges, were more likely to quit smoking for six months or more than people using just one type of NRT.

Does the dose matter?

 Using higher dose nicotine gum made successful quitting more likely than lower dose gum (4mg of nicotine versus 2mg). The evidence is less certain on doses of nicotine in skin patches, but higher dose nicotine patches (containing 25mg or 21mg) probably make quitting more likely than lower dose patches (15mg or 14mg).

Starting NRT before quitting may help

This is something we need more evidence to be sure about, but it seems that starting NRT before ‘quit day’, the day on which someone stops smoking, probably improves the chance of success.

Is NRT safe?

It’s always important to know about the potential harms as well as benefits of any treatmentSomething done with the aim of improving health or relieving suffering. For example, medicines, surgery, psychological and physical therapies, diet and exercise changes.. Most of the studies didn’t look at this! Those that did found that very few people experienced harmful effects of NRT and those mentioned were minor, such as skin irritation with patches. The evidence does not indicate that risks are increased when more than one type of NRT is used. NRT is considered to be safe, but little is known about how different types of NRT compare in terms of harmful effects.

Where does this leave us?

Lead author, Dr Nicola Lindson from the Nuffield Department of Primary Care Health Sciences, University of Oxford, UK said “This high-quality evidence clearly signposts that the most effective way to use NRT is to use a combination of two products at once, a patch and a fast acting form such as gum, nasal spray or lozenge. Quitting this way increases the chances of you stopping smoking altogether.”

Dr Lindson also highlighted the questions that the existing researchThe term research means different things to different people, but is essentially about finding out new knowledge that could lead to changes to treatments, policies or care. doesn’t answer, including how long NRT should be used for and whether it makes a difference to successful quitting if smokers pay for NRT or have it provided for free.

This leaves plenty of work for researchers to do, while producers of prescribing guidelines will need to consider the findings of this review. For smokers wanting to quit, it’s good to know that this review has some high-quality evidence to inform their decisions about using NRT to help them. For those who’ve managed to quit, catch up with this blog from Robert Walton on how to keep up the good work!

Join the conversation on Twitter with @CochraneUK @CochraneTAG @SarahChapman30 or leave a comment on the blog.

References may be found here.

Sarah Chapman has nothing to disclose.

Page last updated 31 May 2019