A world-first therapy for helping smokers quit that uses a nicotine-filled inhaler – similar to what asthmatics use – in combination with a nicotine patch has doubled quit rates compared to smokers using a nicotine patch only.
Lead researcher Professor Julian Crane from the University of Otago, Wellington, and his team developed the pressurized metered-dose inhalers with Auckland-based company Argenta Ltd. They then completed a clinical trial of 502 New Zealand adult smokers with a history of repeated quit attempts.
One group were given the nicotine-filled inhaler and nicotine patch to use for six months while the other group received a placebo inhaler and a nicotine patch. Participants were told to use the inhalers whenever they felt an urge to smoke.
Both the development of the nicotine-filled inhalers and the clinical trial were funded through a Health Research Council of New Zealand (HRC) project grant worth $1.35 million.
The results from the clinical trial, which were published online this week in the peer-reviewed journal Nicotine and Tobacco Research, showed that participants in the nicotine-filled inhaler group were twice as likely to have abstained from smoking over a period of six months than those in the placebo group – where abstinence was defined as not having smoked on seven consecutive days.
HRC Chief Executive Professor Kath McPherson says although New Zealand’s smoking rate is decreasingly slowly, it remains stubbornly high in Māori and Pacific adults and in adults living in the most deprived areas.
“This unique study provides the first evidence that inhaled nicotine from a simple standard inhaler – similar to those used for many decades to help treat asthma – could substantially increase a smoker’s chances of quitting,” she says.
Using the nicotine-filled inhalers and nicotine patches provides a baseline level of nicotine combined with a rapid top up for acute cravings. Professor Crane says the doubling of the smoking quit rates in the trial using this method was especially impressive because the placebo group were already receiving the best current nicotine replacement therapy available. And those using the placebo inhaler plus nicotine patch actually had better quit rates than in many studies of using a nicotine patch alone.
“As nicotine levels begin to drop, people start to crave it. The inhaler seems to fill the gap for people instead of reaching for a cigarette – it provides hand and airway stimulation and a large dose of nicotine,” says Professor Crane.
“The placebo inhaler also has menthol in it to mimic some of the effects of the nicotine-filled inhaler. Menthol reduces the irritant effect of nicotine on the airway – it’s like inhaling a whole lot of peppermint. We think the airway sensation of the menthol might also have helped them to keep off cigarettes.”
The nicotine-filled inhaler wasn’t without its side-effects: most people coughed a lot when they first tried it. However, Professor Crane says their coughing reduced significantly with repeated use, which is exactly what happens when people start smoking.
There is considerable worldwide interest in inhaled nicotine from e-cigarettes, yet there has been little evidence to date as to whether they are effective at reducing smoking or not.
Professor Crane says the inhaler has a distinct advantage over e-cigarettes.
“One of the major criticisms of e-cigarettes is that they imitate smoking behaviours. Our inhaler doesn’t look like a cigarette or mimic smoking behaviours in any way. It can also be used anywhere where you might use an asthma inhaler, including on planes,” he says.
The researchers are now looking into licencing and manufacturing the nicotine-filled inhaler on a large scale so it could be made available to all smokers who would like to use it.