What is the evidence for nicotine vapes and smoking cessation? We asked the experts…

When Health Minister Mark Butler announced plans for sweeping reforms to reduce access to vapes last year, he included one major caveat.

Prescriptions for nicotine vapes would become much easier to get, as GPs would no longer need to be authorised to prescribe them.

“There is still a therapeutic use for vapes in the right circumstances – to help long term smokers quit cigarettes,” Minister Butler said at the time.

Under new rules that came into effect this year, GPs and nurse practitioners can prescribe vapes without prior approval under Special Access Scheme C. This requires them to submit a notification form to the TGA within 28 days of prescribing.

But misinformation about vaping abounds, and Healthed’s survey data has consistently shown that GPs are reluctant, and in many cases diametrically opposed to prescribing it.

What does the evidence say?

An updated January 2024 Cochrane Review found high certainty evidence that quit rates are significantly higher with nicotine E-cigarettes or vapes, compared with nicotine replacement therapy (NRT).

• The review, which included 88 studies and more than 27,000 participants, found high certainty evidence that eight to 10 out of 100 people might stop smoking for six months or longer using nicotine vapes, compared to six out of 100 people who use NRT such as patches or gum.
• There was moderate certainty evidence of no difference in adverse events between vaping and NRT, and low certainty evidence of no difference in serious adverse events.

The Cochrane team has explained that high certainty evidence means that “further studies are unlikely to change our effect estimate in a way that would alter its clinical interpretation.”  Moderate certainty was “because we simply don’t have that many studies and those that we have, we don’t have much data, while low certainty was due to “even fewer studies with even less data.”

“It’s the most effective and it’s the most popular quitting agent and it should be available to smokers who can’t quit with other methods,” says Dr Colin Mendelsohn, a former GP who now specialises in tobacco treatment.

Along with the Cochrane Review, Dr Mendelsohn cites a 2021 systematic review and network meta-analysis of 171 RCTs from the National Institute for Health and Care Research (NIHR) in the UK, which found vaping was the most effective quitting agent.

Differing views on certainty of evidence

The RACGP expert advisory group on smoking cessation reanalysed the Cochrane review’s evidence with the help of an external group, and rated it as “moderate certainty.”

While this was a grade lower than the Cochrane team had rated the evidence, it was higher than the advisory group’s previous rating, according to Professor Nick Zwar, who chairs the RACGP expert advisory group on smoking cessation.

“This was a grade up from our previous one of low certainty, so the additional studies supported the conclusion that nicotine vaping was more effective—not a lot more effective— but more effective than nicotine replacement therapy in reducing smoking for six months or more,” Professor Zwar says.

Professor Emily Banks, head of the Centre of Epidemiology for Policy and Practice at Australian National University is the lead author of a 2023 review which deemed the evidence for vaping for smoking cessation as “limited.”

“The Cochrane Review had different criteria to us,” Professor Banks explains. “About 30% of their data on NRT (nicotine replacement therapy) and E-cigarettes is from a study that wasn’t actually published. It was published as an abstract but not as a full paper. And it was industry sponsored and it also wasn’t pre-registered.”

“We’re currently updating our review, but we couldn’t include that study because it just didn’t meet our criteria,” Professor Banks continues, adding that the Cochrane reviewers tended to give more favourable risk of bias ratings on the evidence than her team did.

The review by Professor Banks and colleagues was commissioned by the NHMRC to inform policy, and thus covers a broad range of topics, rather than focusing solely on the role of vaping for smoking cessation as the Cochrane Review did.

Overall, Professor Banks says vaping “does help some people quit smoking,” but the lack of rigorous safety data and no registered product is problematic.

What the Australian guidelines say

In January the RACGP released updated ‘provisional’ advice around ‘therapeutic vaping’ to support smoking cessation – with additional information on helping people quit vaping.

The provisional guidelines continue to recommend nicotine e-cigarettes as second line therapy for people who have not succeeded with one of the approved pharmacotherapies, and after a discussion about the uncertainties around long term safety, as well as the risks of ‘dual use’ of both smoking and vaping—with a goal of stopping smoking and stopping vaping in the longer term.

Safety

A comprehensive review of the evidence on the safety of nicotine vaping commissioned by England’s Office for Health Improvement and Disparities and published in late 2022 concluded that: “In the short and medium term, vaping poses a small fraction of the risks of smoking.”

The researchers said vaping is not risk-free, particularly for people who have never smoked, and that evidence is “mostly limited to short and medium term effects.”

They said long-term studies with more standardised methodologies are needed, but they found “significantly lower exposure to harmful substances from vaping compared with smoking.”

“There is no vaping product that’s had a full assessment as a medicine. And there continues to be a lack of evidence on the long-term safety,” Professor Nick Zwar says, noting recent studies that have raised concern around oral health and cardiovascular effects. “But it probably depends on how long you use it for. So if you use it short term, the risk may not be that substantial when you compare them to the risk of continuing to smoke.”

“If you’re comparing it to just breathing in clean air, yes, clearly it’s going to have more risk, but if you compare it to someone who might otherwise be using combustible tobacco, that changes the way you think about risk,” Professor Nick Zwar says.

Far fewer chemicals in vapes than in combustible tobacco

Dr Colin Mendelsohn says there’s no question that vaping is far safer than smoking, and argues that given vapes contain significantly fewer chemicals, we can extrapolate that they are likely to be safer in the long term, too.

“The Royal College of Physicians says even long-term vaping is likely to be no more than 5% of the risk of smoking. We don’t need to wait 50 years to know that because there’s huge amounts of chemicals in tobacco smoke, over 7000 chemicals in high doses. In vapour there’s about 100-200 chemicals typically, mostly they’re less than 1% of what they are in smoke,” he says.

However Dr Mendelsohn believes pervasive misconceptions may be part of the reason doctors are so reluctant to prescribe vaping for smoking cessation.

For example surveys have shown that many doctors mistakenly believe nicotine causes cancer and cardiovascular disease, he notes.

“E-cigarette or Vaping Associated Lung Injury (EVALI) has been primarily linked to vitamin E acetate in vapes that contain THC and is not due to nicotine vaping,” he adds.

Professor Zwar says there is a need for ongoing data and monitoring in larger populations since sometimes safety issues emerge that aren’t picked up in randomised trials, due to the relatively small number of people that take part.

What should GPs be monitoring for?

Professor Zwar says there are a number of things to monitor as you follow up patients using therapeutic vapes.

• Does the person get any new symptoms, such as respiratory symptoms?
• Are there symptoms of nicotine overdose (e.g. nausea, sweating, or other symptoms that they are getting more nicotine than they need)?
• Are they also smoking? (While not a side effect, it’s important to monitor whether they are achieving the desired outcome of transitioning off tobacco)
• How is their dental health? (Recent research has linked vaping with gum disease)
• Are they using other drugs such as cannabinoids?
• Are they pregnant or trying to become pregnant? (Professor Zwar recommends stopping use if someone is pregnant, and potentially offering an alternative such as patches in those cases, which has more evidence for safety.)
• Blood pressure may be worth monitoring, particularly if someone has a history of hypertension, though Professor Zwar notes that the effects of nicotine on blood pressure tend to be a temporary spike immediately after a dose that then returns to normal.

Duration of use is a key consideration

“If you’re thinking about this for three to six months, or something like that, to help people transition off tobacco, the cardiovascular risk, as I’m aware of the literature so far, would not be a major concern. But if someone’s going to keep vaping for 10,15, 20 years, we don’t have that experience yet, but that might be very different,” Professor Zwar says.

Which vapes to prescribe

Currently, there are vaping products from 10 manufacturers, one of which is a major tobacco company, Professor Zwar points out. He recommends checking the TGA’s vaping hub before prescribing.

Prescribers should also be aware that while there are 127 vaping products of different strengths available, they currently don’t come up if you search for “nicotine” in the prescribing software, Professor Zwar adds (noting that many are in the software if you know the specific name to search for).

Transitioning off vaping

Professor Zwar says that given the lack of specific research, the practical thing is to apply what we know about tobacco cessation to vaping—so that includes counselling support, support from family and friends and resources like Quitline, and careful use of pharmacotherapy.

“Sometimes, it will be reasonable to prescribe therapeutic vaping for a period of time as people work out how they’re going to transition…. And that might be that they titrate down in dose and frequency of use over time. Or it might be they do that then they transition on to nicotine replacement therapies such as patch or gum or a combination of patch and gum – or sometimes it might be transitioning onto a medicine like varenicline.”

Barriers to prescribing

The lack of a regulated vaping product remains a major barrier to prescribing vapes, Professor Banks and Professor Zwar agree.

“GPs in Australia are being told prescribe these, but they actually haven’t been through any kind of drug regulatory processes. And that’s because the industry is not submitting them for that. So they’re promoting them to the community saying this is great for smoking cessation, but they won’t put them through any of the safety stuff,” says Professor Banks, who also previously chaired the Advisory Committee on the Safety of Medicines.

“If something is going to be a registered product, you have to be able to determine its safety profile, which is where you have very limited information,” Professor Banks adds.

“It’s not just about whether they’re efficacious. It’s about efficacy and safety as well. The other products we have for quitting smoking, that are recommended, actually have been through the regulatory process. They’re registered, their safety is known,” Professor Banks says.

Professor Zwar agrees that the lack of a registered product has contributed to doctors’ reluctance to prescribe.

“I think it is confusing for doctors. And it’s an area where there are some uncertainties,” Professor Zwar says.

To date there have been few educational opportunities for doctors to learn more about therapeutic vaping, which is a problem since the regulatory changes have been happening so fast, he adds.

“These changes are coming in over the course of this year. There is a bill before Parliament at the moment, and disposable vapes are now banned. So the current supply already in the country is gradually being used up,” Professor Zwar explains.

“If that ban is effective, then in the fairly short future, people will go to their vape shop will not be able to get disposable vapes, which are the most widely used form. So that will be a challenge in terms of what they do to support their nicotine use, because most of them are nicotine dependent.”

For more information

Electronic cigarettes for smoking cessation  | Cochrane Library

Electronic cigarettes and health outcomes: umbrella and systematic review of the global evidence | The Medical Journal of Australia

Supporting smoking cessation: A guide for health professionals | RACGP

Guidance on the use of vapes for smoking cessation or the management of nicotine dependence | Therapeutic Goods Administration