Overcoming problems with asthma therapy
Choosing treatment and when to refer
What are the indications for referral to a specialist in the management of asthma?
I think there are a number of indications, some of which reflect the expertise of the specialist and some are simply a feature of primary care management.
· If there is any uncertainty about the diagnosis.
· If there is patient pressure for referral to confirm the diagnosis or to confirm that the treatment is appropriate.
· If there is a failure to respond to treatment.
· If there are any occupational issues: if it is thought that the asthma may be due to an occupation exposure.
· If the patient needs specialised treatment such as subcutaneous terbutaline or continuous oral steroids or if it is thought that they may need regular home nebulised therapy then I think it's worth referral to a specialist for assessment before instituting those treatments.
· Finally, there is the referral to hospital in the case of acute exacerbations.
What are the current indications for using leukotriene receptor antagonists?
I think this class of drugs has been rather disappointing.
The leukotrienes appeared to be pivotal mediators in asthma and the idea of blocking them looked as though it would have a major effect in reducing airway inflammation and causing bronchodilatation.
Now, the best evidence suggests leukotriene receptor antagonists are about as effective as low-dose inhaled steroids, so the indications are fairly limited.
There is an indication at step three of the current British Thoracic Society (BTS) guidelines if somebody has failed to respond to long-acting ?2-agonists and for whatever reason you are not keen on pushing the dose of inhaled steroids higher.
In these circumstances, leukotriene receptor antagonists are worth a try and anecdotal experience is that about 50 per cent of patients respond to them.
When are nebulised steroids used?
The role of nebulised steroids is still controversial. There are a number of
studies now that show there is the
potential for a reduction in the dose of oral steroids.
I think one of the principal roles of nebulised steroids is in an oral steroid sparing agent.
Equally, as a step-up measure, patients may prefer to go on to high-dose nebulised steroids rather than taking oral steroids, but there is some evidence that the systemic side-effects are just the same with the equivalent anti-inflammatory dose of nebulised or oral steroids.
There are, of course, also disadvantages in terms of oropharyngeal candidiasis and the time it takes to take the nebulised steroids.
On balance, I think the indications are relatively few, but a few patients do quite well with this therapy and it is an option for the more severe patient.
What's in this article · Choosing treatment and when to refer · Significant differences between inhaled steroids · Overcoming problems with asthma therapy
· Choosing treatment and when to refer
· Significant differences between inhaled steroids
· Overcoming problems with asthma therapy
What osteoporosis prevention do you use with people on inhaled steroids ?
With doses of inhaled steroid above 1500mg of beclometasone (or equivalent doses of budesonide and fluticasone) it is important to consider osteoporosis prophylaxis. It is worth trying to assess bone density in younger patients, to see whether they need to start prophylaxis now or whether just a fitness programme, regular exercise and maintaining adequate calcium intakes are sufficient. In the older patients who are at risk of osteoporosis on high-dose inhaled steroids, there are clearly a range of options, but I think the most effective therapies available are hormone replacement therapy and/or a bisphosphonate.
When should we use a home nebuliser?
I think the role of home nebulisers in asthma is very debatable. There is no evidence that the same dose of drug delivered by nebuliser is any more effective than if given by a metered dose inhaler in a large volume spacer. The advantages of a nebuliser are that it obviously takes less time to give the same dose of drug, but of course there is the view that if the patient is needing large doses of
?-agonists then perhaps they need their basic anti-inflammatory therapy adjusted. In these situations it may be dangerous to rely on nebulisers.
In a rural setting like ours then I think there is a role for patients having nebulisers at home if the nearest ambulance or on-call doctor is some time away. At times of acute exacerbations they can use the nebuliser as a holding measure until help arrives.
Do you have any tips on the 'brittle asthmatic'?
The first thing is to define the terms. Brittle asthma classically is divided into type 1 and type 2. Type 1 have random, chaotic variation in their peak flow which seems completely unrelated to any external stimuli. These patients are quite difficult to manage but sometimes do well with a long-acting
?-agonist or subcutaneous terbutaline, if the inhaled therapy fails. In patients who appear to have continuing symptoms despite being on high doses of therapy, I think there are several things to address.
Are they actually taking the medication as prescribed? Are they able to use the device? Are there external stimuli fuelling the asthma and leading to continuing symptoms (this may be pet aero-allergens or occupational factors that is making their asthma persist despite therapy)?
The type 2 brittle asthmatic presents a really difficult problem. These are the people who are apparently extremely stable most of the time but then have catastrophic falls in their peak flow and bronchoconstriction in response to an external trigger.
They can go from being completely fit and healthy to being dead within 20 minutes. These people are the ones who it's best to issue the prefilled adrenalin syringes so that at the first sign of deterioration in their asthma, they can self-administer the adrenaline.
Significant differences between inhaled steroids
Do theophyllines have any effects other than as a bronchodilator?
This is an issue that goes round and round in fashions. Current thinking is that theophyllines have a mild anti-inflammatory effect at low doses. These are below those that would be considered therapeutic bronchodilatatory concentrations.
Interestingly, there is some recent work suggesting they may act in a similar way to steroids in unmasking genes that are anti-inflammatory. But in clinical practice, I think that side-effects tend to limit their use.
Do steroids in childhood lead to growth retardation?
Again, this is something where opinions have changed. Current evidence suggests high-dose steroids, particularly fluticasone in children, can lead to growth retardation. As you know, the early data suggested asthma itself was a significant cause of growth retardation in children and that by treating asthma effectively with inhaled steroids, you restored normal growth velocities.
Increasingly, as asthma has been better controlled the concerns about growth retardation have recurred. There is now some evidence for a slowing of growth and sufficient studies now to suggest one should be cautious about using high doses of inhaled and certainly oral steroids in children.
Is there any evidence of one inhaled steroid over any others?
There are significant differences between both budesonide and fluticasone and beclometasone, particularly in terms of the first pass metabolism and potential for systemic side-effects. If you try to balance the evidence fairly, then comparing equivalent anti-inflammatory doses deposited in the lung, I don't think there is any good evidence to suggest either fluticasone or budesonide is any better in terms of having more anti-inflammatory potential or fewer systemic side-effects.
Which inhaled steroid do you use by preference?
The choice of inhaled steroid is more complicated than simply just which molecule you use because obviously the device that it comes in must also be considered. In my experience I tend to think that budesonide in a turbohaler is a better combination than fluticasone in either a metered dose inhaler (MDI) or an accuhaler.
When I am starting steroids, I think most will be able to use a MDI. If they are not able to use this, then I switch to budesonide in a turbohaler and occasionally use fluticasone in an accuhaler. I prefer the turbohaler because it's easy to use (I think most patients can generate sufficient inspiratory flow) and the pulmonary deposition is better than with an accuhaler.
In primary care there will be a costing issue because certainly budesonide as a turbohaler is one of the most expensive options for prescribing inhaled steroids. Is that a problem in secondary care?
Well, cost should always be borne in mind, but obviously cost-effectiveness is obviously more important than cost alone. By using a slightly more expensive device you may push up initial costs but you may subsequently reduce costs by having better control of asthma, with fewer hospital admissions and fewer complications for the patient.
Which spacing devices suit which patients best?
I don't think there is an easy answer to this question and this is where the skills of the practice nurse come in. All asthma therapy and all devices need to be matched to the individual patient.
The small volume spacers are more convenient but studies have shown that they're less effective at reducing droplet size and slowing down the particle cloud than the large volume spacers. Some spacers are not designed to be used with certain inhalers and it is obviously important to match the inhaler with the spacer device.