Norman Swan: Now there are various ways to quit smoking. Some people do it cold turkey; some people do it with nicotine replacement; some take a medication called Varenicline, and some people take support from the Quit Line to get through the ups and downs and occasional failures before success.
In Europe, though, there’s a herbal compound called Cytisine, which has had some evidence to support its use. It’s a fraction of the cost of Varenicline, and a trial has commenced in Australia with a view to getting it approved for use. The person running the trial is Ryan Courtney of the National Drug and Alcohol Research Centre at the University of New South Wales. Welcome to the Health Report, Ryan.
Ryan Courtney: A pleasure to be here, Norman.
Norman Swan: What exactly is Cytisine?
Ryan Courtney: Cytisine is a natural plant extract commonly found in the laburnum plant throughout Europe, but there are lots of species here in Australia that do also contain the cytosine extract…
Norman Swan: How does it work, if it works at all?
Ryan Courtney: Okay, so it works as a smoking cessation medication and it tries to reduce…well it does, actually, it’s been shown to reduce cravings and withdrawal symptoms for smokers when they’re undergoing a quit attempt.
Norman Swan: And there’s a purified form of it available, or do you munch the leaves?
Ryan Courtney: It’s a 1.5 milligram that goes into a capsule, or a tablet, at the moment.
Norman Swan: What evidence is there that it works?
Ryan Courtney: The current evidence, there’s been a couple of really high quality studies, so two placebo control trial studies as well as one head-to-head pragmatic trial that compared it to nicotine replacement therapy with over 1200 smokers in New Zealand, and it was found to be more effective than nicotine replacement therapy for cessation, for quitting.
So it’s quite promising in terms of the results, but there’s been no head-to-head comparison compared to Varenicline or Champix, which is currently the frontline and best smoking cessation medication currently available in the world and that’s what we’re trying to establish, is whether or not it is just as effective as Varenicline for quitting.
Norman Swan: So you swallow a capsule. How many times a day?
Ryan Courtney: It’s quite a number of tablets per day. It’s a shorter course, it’s only 25 days compared to Varenicline but it does, the dosing regime does, similar to Varenicline, include a number of tablets per day over a period of 25 days.
Norman Swan: And it’s cheaper.
Ryan Courtney: That’s what we’re looking at. We’re trying to find out the effectiveness, so what the rates of cessation look across both groups and then compare the healthcare costs associated with using Cytisine. But at the moment it looks like it will be a lot cheaper, as it is a natural plant extract that is easily manufactured.
Norman Swan: So why isn’t it approved here, for there’s a couple of trials, one in Europe, one in New Zealand; I think there’s more than that, actually, showing that it works. Isn’t that enough to get the authorities to approve it?
Ryan Courtney: I guess it’s a case of…it’s a medication that’s had a very unconventional history. If you were to talk to someone in Russia or even parts of Eastern Europe they’d say, ‘Well why aren’t you guys using Cytisine?’ But generally…
Norman Swan: Why aren’t we?
Ryan Courtney: Yes, why aren’t we in Australia. It’s generally an artefact of trying to get more high quality evidence with larger studies like we’re doing, and also trying to look at not just effectiveness but safety as well. So the current studies haven’t been done to the highest contemporary standards that are required, and it wasn’t until about the mid-2000s when the really big placebo control trial study came out and there was a review that looked at Cytisine’s efficacy and found that it did look positive. And then the head-to-head trial happened in New Zealand against nicotine replacement therapy, and the results were quite positive and interesting.
Norman Swan: What are the side-effects?
Ryan Courtney: The side-effects are currently mild to moderate slight gastrointestinal symptoms, but not unusual compared to some of the other medications that are currently available, like nicotine replacement therapies and Varenicline. We’re not necessarily expecting a higher rate, but we’ll be carefully tracking adverse events throughout the study when participants are in the study to get to that outcome.
Norman Swan: And what you’re looking for is a quit rate.
Ryan Courtney: Yes, that’s exactly right, Norman, Yes.
Norman Swan: And if somebody wants to participate in the trial, what’s involved?
Ryan Courtney: What’s involved is generally a…so first of all an expression of interest so they can find out about our study through your website, of course, on the Health Report, and they’ll call up or email and go through an eligibility or screening process, so they have to be a daily smoker. Currently we’re only recruiting through the Sydney Metropolitan and a little bit wider area at the moment.
Norman Swan: So there’s a bit of a problem for our Perth listeners.
Ryan Courtney: Yeah, it does make it a little bit harder. But that’s the limitations of a clinical trial where you have to look at the outcome as well, which is often validated self-report.
Norman Swan: Has the horse bolted here, are herbalists flogging this already for smoking?
Ryan Courtney: No, I don’t think the horse has bolted. If it had a lot of people would have had access to it and using it. Not just in Australia as a potential option but also in low to middle income countries where currently the price of smoking cessation medication is just cost-prohibitive.
Norman Swan: Well in return for letting you advertise for more people on your trial, we hope to get the results first here on the Health Report.
Ryan Courtney: Definitely, for sure, Norman. I really appreciate it.
Norman Swan: Thanks very much. Ryan Courtney is Research Fellow at the National Drug and Alcohol Research Centre at the University of New South Wales.