- 02 Dec 2022
- 15 min 54
- 02 Dec 2022
- 15 min 54
Justin Coleman chats with Professor Nick Zwar about the latest changes to the Australian Asthma Handbook. These include updated advice on exercise-induced asthma, dosing information, and use of e-cigarettes for smoking cessation.
The risk of death is when people are using more than 10 puffs a day of SABA, but we obviously would want to have it well lower than the risk of death. If I see someone who's needing to use their SABA every day, I definitely think they need a reliever and I would not want them to be needing to use their SABA more than three or four times a week.
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Hi, and welcome to this Australian Prescriber podcast. I'm Dr Justin Coleman, a GP in the Northern Territory where I'm Director of Education for NTGPE, but I also flit to Queensland backwards and forwards where I do some real work and see patients in Brisbane. And I'm joined today by my fellow Queenslander, Professor Nick Zwar, who applies his trade on the Gold Coast at Bond University, where he's Executive Dean of the medical faculty. But in this capacity, Nick, we've invited you on as chair of the Australian Asthma Handbook Guidelines Committee. Welcome to our humble podcast, Nick.
And today we're talking all things asthma. There was a new update recently put out by the Australian Asthma Handbook, and we just wanted to pick through a few things which have changed compared to previous editions of the book. Asthma is something clearly all GPs see a lot of, and pharmacists who are listening in will have a lot of inquiries about various puffers. First, I wanted to ask you about exercise-induced bronchoconstriction, and it can sometimes be a bit of a confusion for us as to when to treat it with those short-acting bronchodilators, the SABAs, and when to move on corticosteroids. And I think there's some new updated advice in your guidelines.
Yes, that's right, Justin. And it's updated advice for adults and adolescents, and also advice for children. So for adults and adolescents, the key messages here are that it's important to ask about asthma symptoms and assess whether the extent of the asthma symptoms would justify someone being on a reliever in the longer term. So for example, if a person was experiencing asthma symptoms twice a month or more, or getting risk factors for flare-ups, they may have come into you to talk about their exercise-induced asthma. But if you ask those questions, you may realise that actually this person is suitable or would benefit from using a preventer in a more long-term way. That is something to then pick up on. But you would also want to give them advice about what to do before exercise. And that might be having assessed whether or not they need to be on a longer term treatment.
You would also advise a person to use their reliever inhaler, and that might be just salbutamol, just a SABA, or it may be combined inhaled corticosteroids, formoterol. So that is the maintenance and reliever therapy, 15 minutes before exercise, if needed. Often though, if you have put the person on a preventer, it may be that within two to four weeks, they will find that their exercise-induced asthma comes under control and they don't need to do that. It may take a bit longer, it may take up to 12 weeks. But if they do need to do that, then they can use either their short-acting beta agonist or their combination ICS and formoterol 15 minutes before exercise. So that's in adults and adolescents.
And then in kids, it's somewhat similar advice. You're asking about does this child have more persistent asthma symptoms that might justify a preventer? And if they do, then you would want them to start using that. Otherwise, you would again suggest them using salbutamol and it's usually a metered dose inhaler in that case. And they may use a spacer, and it's typically one to four puffs, again, 15 minutes before exercise. I guess in kids, though, you might be thinking about slightly different options for longer term treatment, should it be needed for the kids who are getting asthma symptoms, and whether that's a low-dose inhaled corticosteroid or might be montelukast as another option? But that gives you an idea about thinking about does this person just have exercise-induced asthma or actually is there a more persistent asthma problem we need to be treating?
So I gather there's been a general move over the last decade or so to lower the threshold for that preventative treatment in exercise-induced asthma. Is the reason for that, that often there's more of an underlying symptom which perhaps they don't highlight when you ask the people? Or is it more a safety thing?
It's more of the former that there may be underlying symptoms, which if you ask about them will become clear, that they're having nocturnal cough or they're getting flare-ups, but they don't present with that necessarily. They present with, "Oh, when I run I get wheezy." And it's only if you ask about that, that further history comes out. And as I said that if you then manage that more persistent asthma, actually their exercise-induced asthma comes under control and they don't even need to use a reliever ahead of their exercise.
And along those same lines, there's a discouragement of using SABAs alone more these days. So in the past, certainly we used to have quite a number of people on the short-acting beta-2 agonists, salbutamol being most common, and it was somewhat of a free for all. People could go and get them and get as many puffers as they wanted and puff away to their heart's content. The new guidelines do give some indication as to how many puffs are reasonable to expect to use in that fashion, and then when you get to a certain point, we really need to be looking at more preventative options.
Yes, that's right. That's become evident. There are risks with excessive use of SABAs, and there have been asthma deaths that have been attributed to people just using those medicines and not a preventer. And so if people are needing SABAs frequently, then that is something that we would like to pick up and provide guidance on using a low-dose ICS, which will usually decrease the need for SABAs quite substantially. And if people are still needing SABAs, to then escalate therapy using the Selecting and Adjusting Asthma Medication chart, which is on the National Asthma Handbook website and gives us sort of step-up recommendations.
And of course that treatment could be what's been the traditional thing of a low-dose ICS along with still some SABA or it may be the maintenance and reliever therapy option where people use the combination of budesonide and formoterol both as their preventer, and if they're getting a flare-up, also as their reliever. So they just have the one puffer for both purposes. So that's not new to this edition of the guideline, but that is certainly something to consider if GPs are thinking, "Well this is a person that I think needs to be having a preventer, what's my approach? Is it the low-dose ICS–SABA approach or is it the maintenance and reliever therapy approach?"
And that maintenance and reliever therapy can certainly be useful I find for younger, busier people who either forget to go out with a spacer or don't like using it and prefer one puffer instead of two. And I think for that sort of person having something where the formoterol has a rapid onset of action, more rapid than salbutamol and it does help relieve symptoms I gather within minutes, I think that can be a good positive feedback for them that they're doing the right thing and their adherence to medication tends to go up.
I agree. And I think the other thing is, there's been a tendency to put people on more ICS than they probably need, and that's probably quite reasonable if you are starting someone in a context in a more acute attack and they need a higher dose to bring it under control. But we really need to be trying to get that person back so that we can review the dose and titrate down to a low dose. Because for most patients with asthma and say you're using the ICS SABA approach, beclomethasone, it might be only 200 micrograms a day, budesonide up to 400 micrograms a day, fluticasone one or 200 micrograms a day. These are not high doses. And so back-titration is an important part of asthma management.
The updated guidelines do have some information about how much SABA alone is the threshold. In general, it's lower than it was previously. Could you give us some sort of indication as to when we should be looking at bumping up from a SABA alone?
The risk of death is when people are using more than 10 puffs a day of SABA, but we obviously would want to have it well lower than the risk of death. So I guess as a clinician, if I see someone who's needing to use their SABA every day, I definitely think they need a reliever and I would not want them to be needing to use their SABA more than three or four times a week.
Happily the pharmacists are well educated in this. I think, and certainly in recent years I've had more patients come to me and said, "Oh, I just went to get my puffer from the pharmacist and they told me I had to see you instead." So I think that's a great backup if the person is buying over the counter. Just finishing off the medications before we move on. I didn't know that the chromones have been discontinued, so I used to use a bit of sodium cromoglycate, also nedocromil sodium. What's the story there?
Yes, they're not available anymore. I agree. I used to find them quite useful in children, not useful in adults, but as I understand it, the degree of use was quite low and it wasn't economic for the companies to continue to provide them. Not that they're unsafe in any way as far as I'm aware.
Let's move on now to something which really has been a rise and rise recently. And that's electronic cigarettes. So certainly, vaping stores and shops are opening up left, front, and centre. But happily the new guide spends a fair bit of time talking about the use of electronic cigarettes. Just to clarify, it's still right, is it, that you theoretically are not allowed to buy nicotine containing e-liquid in Australia without a prescription?
Yes, that's absolutely correct. And that's been the case since 1st of October last year. And Australia's unique around the world in making nicotine vaping products only available legally on prescription. And so that's been a challenging thing for GPs to negotiate, given that there's no approved nicotine vaping product as a medicine. And so that we are left in a tricky situation of not having a medicine that we could use with all the assurances and testing that comes with full TGA approval in that category.
Could you give us your take on where you feel electronic cigarettes, as a prescription with the purpose of reducing and quitting smoking, where do they fit in currently?
Well, the RACGP smoking cessation guidelines say that they're certainly not first-line therapy for supporting smoking cessation, and people should be encouraged to try the approved pharmacotherapies, nicotine replacement therapy and varenicline and bupropion being options there, as the much more proven and known-to-be-safe alternatives. Having said that, if people have not been able to successfully quit using those approved therapies, there may be some patients who you would consider prescribing nicotine vaping products. But there's a number of considerations and caveats around that, and the patient needs to understand that we do not know the long-term health effects of vaping. The dual use of vaping and tobacco is a real problem, and if people aren't able to completely stop tobacco and transfer over to nicotine vaping and then transfer off nicotine vaping, they will not get the health benefit. There isn't an approved product, so you don't quite know what you are going to get in your nicotine vaping product.
I mean, there are some TGA standards for products that are dispensed in Australia, which are helpful to make sure that there's not known harmful molecules in say the flavourings or the things that help to make the liquid vaporise. But the long-term effects of the things that are there are not known. So there's a range of considerations there, and it's not an easy decision for GPs and other prescribers to get involved in providing that service. But if people do get involved, the guidelines would suggest doing it through the approved prescriber pathway, where you go through the TGA process of becoming an authorised prescriber and then prescribing through an Australian pharmacy because then you know that the product will meet the TGA standards for products that are coming in via that pathway. The other thing I just should mention is that there haven't been studies specifically in people with asthma about the safety or effectiveness of nicotine vaping products for smoking cessation in that population.
I guess there is a bottom line that if in fact it was a pure decision between smoking cigarettes and smoking a vape thing, clearly the vape would win out. The difficulty is in the real-world situation. It all gets mixed up in the way people use it and use it to quit smoking. Is that about right?
There is some evidence on effectiveness. There have been a number of randomised trials comparing nicotine vaping with nicotine replacement therapy and showing that vaping appeared in those small number of studies to be slightly more effective. Now having said that, that's a small number of studies. Most of them didn't have long follow-up, and there's a whole range of considerations like whether people who were using the nicotine vaping products then were not able to stop using them or continued them even longer than was intended. And I think it's important to realise that the heated aerosol, it's not smoke, it's a warmed aerosol, so they shouldn't be combusting anything, but there are risks and certainly disposable vaping products, which are unfortunately very commonly coming into the country illegally and being used by young people, are a real hazard. They've quite a high concentration of nicotine. They've got a battery in them, which makes them an environmental disaster when they're thrown away as litter and their design is such that they have a nicotine wick that comes up against the heating element and that may produce more harmful molecules than other designs of vaping devices. So they are absolutely to be avoided.
Well, thank you very much. That's taught me a lot today. And this is of course, just touching on some of the new things in the new edition of the Australian Asthma Handbook Guidelines, and I've been talking today with Professor Nick Zwar, who is chair of those guidelines. Thanks so much for running us through that, Nick.
My guests’ views are their own and don’t represent Australian Prescriber and my views are certainly all mine.