Experts urge vaping discretion
Researchers say doctors should be cautious about prescribing vaping to help quit smoking.
In the absence of guidance from the Therapeutic Goods Administration (TGA), researchers have provided advice to GPs about prescribing e-liquids for e-cigarettes to smokers trying to quit tobacco.
Although the TGA had released a Standard for Nicotine Vaping Products (TGO 110) effective from 1 October 2021, the order “does not refer to e-cigarettes themselves (which remain unapproved by the TGA as smoking cessation devices), but rather the nicotine-containing liquids (e-liquids) used in them”, according to experts.
Since 1 October, e-cigarette users can only legally access e-liquids containing nicotine locally with a prescription from an authorised prescriber or via a special access scheme through an Australian pharmacist registered to supply nicotine.
“TGO 110 provides no guidance to GPs as to how to manage e-cigarette prescriptions, but Royal Australian College of General Practitioners guidelines advise that doctors should promote approved nicotine replacement therapies (NRTs) and proven pharmaceutical therapies accompanied by behavioural support before considering e-cigarettes,” say the authors of a new article in the Medical Journal of Australia - Dr Miranda Ween, a Senior Postdoctoral Researcher at the Royal Adelaide Hospital, Associate Professor Alexander Larcombe, of Curtin University and the Wal-yan Respiratory Research Centre, and Dr David Chapman, from the University of Technology Sydney.
“As always, doctors should use their own judgement of a patient’s intent before prescribing any medication.”
The authors provided advice on a number of issues, including the concentration of nicotine.
“At present, there is little evidence as to the ‘ideal’ nicotine concentration in e-cigarettes to help tobacco smokers to transition to complete nicotine abstinence,” they said.
“However, e-liquids containing 18 mg/mL have been shown to reduce cravings to a similar extent as traditional tobacco cigarettes, and have been reported as adding small benefits on tobacco smoking cessation above those obtained with NRTs.
“As such, 18 mg/mL, which is close to the EU maximum concentration of 20 mg/mL, may be a prudent starting concentration.”
In regard to behavioural support, they say; “Ongoing structured behavioural support is needed to attain nicotine abstinence … GPs should therefore consider prescribing nicotine-containing e-liquids for short periods as part of an agreed abstinence plan … allowing monitoring of progress and any negative health effects at regular intervals. This is important, as long-term use of e-cigarettes may itself increase the risk of adverse health effects.”
On the matter of flavours, the experts say; “Given that the long-term health effects of e-cigarettes remain largely unknown, unflavoured e-liquids should be preferentially prescribed. It is critical that [patients] be educated that no flavouring chemicals are approved for inhalation and that there is evidence that many pose a risk to health.
“This should be part of the discussion as to why complete abstinence should be the goal rather than long term e-cigarette use.”
There are also questions about nicotine absorption.
“Studies have shown that [some] flavoured e-liquids can significantly increase plasma nicotine levels up to 1.66 fold, likely associated with the effect of flavourants on acidity and nicotine absorption,” the experts say.
“This suppression could lead to vapers using e-cigarettes more frequently, or using e-liquids with higher nicotine concentrations, to elicit the same nicotine reward.
“Taken together, these findings warrant caution in prescribing flavoured e-cigarettes, to ensure that they do not lead to increased and/or prolonged use of e-cigarettes.”