Asthma: management and treatment

UPDATE Clinical chemistanddruggist.co.uk/update-plus

Module 1804

Asthma: management and treatment From this module you will learn:

●●The treatments available for preventing asthma and relieving flare-ups

September ● Asthma: causes and symptoms

3 September*

● Supporting smokers to quit

10 September

● Asthma: treatments

17 September

● Chronic obstructive pulmonary disease

24 September

*Online-only for Update Plus subscribers

●●The side effects of these treatments ●●The different stages of treatment ●●Advice that can be given to a patient who is using a spacer device

Kristoffer Stewart CPD and Clinical Editor

The Qvar inhaler releases extra-fine drug particles, and this makes it almost twice as potent as the Clenil Modulite inhaler. Fostair, which contains beclometasone and formoterol, also has an increased potency compared to some other beclometasone inhalers.

Asthma can be a devastating condition, but with the correct treatment you can help patients to alleviate their symptoms and prevent exacerbations.

Inhaled corticosteroid side effects

Relievers During an asthma exacerbation, the muscles around the airways – the bronchi and bronchioles – contract, causing a narrowing of the airways and restriction in breathing. Reliever medications help relax these muscles, allowing unimpeded breathing. However, they do not have an effect on the inflammation commonly seen in asthma. There are two types of reliever: ●●Short-acting beta 2 agonists (SABAs) – examples include salbutamol and terbutaline, which start to work within a few minutes when inhaled. Their effect lasts for between three to five hours. If a patient’s previously effective dose does not provide symptomatic relief for at least three hours, they should be referred to their prescriber, as they may need to change their dose (see diagram on opposite page). High-dose salbutamol may lead to side effects such as tremor, anxiety, headache, muscle cramp and dry mouth. These usually last a short time and only occur with high doses. ●●Long-acting beta 2 agonists (LABAs) – common examples include salmeterol and formoterol. They take 10-20 minutes to have an effect, but then have a 12-hour duration of action. This is useful for patients requiring long-term regular bronchodilation and those suffering from nocturnal asthma. Some patients using this medication may suffer from side effects such as joint pain, dizziness and nausea. LABAs are not used for the relief of acute attacks, but rather as an additive therapy for patients who have asthma that is not controlled continuously.

Preventers Preventer inhalers help reduce the chances of having asthma symptoms. Inhaled corticosteroids are effective at reducing lung 14 Chemist+Druggist 17.09.2016

Short-acting reliever inhalers work within minutes

inflammation, thereby preventing the oedema and mucous production found in the airways of asthma suffers. By depressing the immune response at the area of concern – the lungs – they halt the inflammatory cycle. In general, the regular use of an inhaled corticosteroid reduces the risk of a patient having an asthma attack. It is therefore vital that patients use their medication as directed. A patient will require prophylaxis with an inhaled corticosteroid if they are using their SABA inhaler more than twice a week, or if they have been prescribed an oral steroid in the two years after suffering an acute exacerbation. The diagram (see page opposite) illustrates the different stages of asthma treatment and shows when a corticosteroid should be introduced; however, the dose will depend on how the patient responds. If a patient is a smoker, or has been a long-term smoker in the past, then this can reduce the effectiveness of inhaled corticosteroids. It is understood that inhaling tobacco smoke can exacerbate the lung inflammation seen in asthma, as well as decreasing airway penetrability. There are a variety of steroid inhalers that contain corticosteroids – such as beclometasone, budesonide, fluticasone and mometasone. Several brands of preventer inhaler contain both a corticosteroid and a LABA. Two different inhalers may contain equal amounts of the same corticosteroid, but this does not mean they are interchangeable. A prime example of this is Qvar and Clenil Modulite, which both contain beclometasone.

By suppressing the immune response on the surface of the throat, corticosteroids can result in an increased susceptibility to infections caused by normally harmless pathogens, such as oral thrush. The risk of developing this condition can be reduced by: ●●using a spacer device (see box on p16), which can help prevent direct contact of corticosteroids with the throat ●●rinsing the mouth out with water after using a corticosteroid inhaler. You can recommend that a patient suffering from oral thrush should use an antifungal suspension or oral gel. You must ensure patients understand that they should still continue to use their inhaler while taking this treatment. Paradoxical bronchospasm – the constriction of the bronchioles after the immediate use of an inhaled steroid – is a rare but serious side effect that may lead to a life-threatening restriction of an individual’s ability to breathe. You can help avoid this by recommending patients use a SABA inhaler prior to using their steroid inhaler.

Leukotriene receptor antagonists Leukotrienes are chemicals produced in the body by white blood cells in inflamed tissue – such as a lung during an asthma exacerbation. When these chemicals land in a receptor site, they contribute to the inflammatory process – leading to swelling, further inflammation and smooth muscle contraction. Leukotriene receptor antagonists – such as montelukast and zafirlukast – are another type of preventer medication that help stop the inflammatory process from taking place. Although they are not more effective at reducing inflammation than inhaled corticosteroids, they have a beneficial additive effect when used in combination.

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Which stage of treatment is appropriate for your patient?

d trolle ot con n s m o ympt ep if s p a st u e v Mo

s ptom ir sym ls the o r t n t co ep tha est st w lo e Initial add-on therapy on th ts are patien ●● SABA when required; and e r u s En

Regular preventer therapy

Mild intermittent asthma ●● SABA when required.

Step 1

●● SABA when required; and ●● inhaled corticosteroid (dosage depends on level of lung impairment).

Xanthines This group acts as a bronchodilator in the management of asthma. Theophylline is the most commonly used; it is typically given in an oral form and used as an add-on treatment in chronic asthma to help relax the muscles and open up the airways. It requires careful monitoring as it has a narrow therapeutic range. When theophylline reaches high concentrations in the body, it can cause severe vomiting, agitation, restlessness, hyperglycaemia, severe hypokalemia, arrhythmias and convulsions. Pharmacists should be aware that patients should not deviate from the particular brand of modified-release theophylline that they start on, as the rate of absorption varies between brands. If a prescription does not specify a brand, you should contact the prescriber to confirm the brand to be dispensed.

Persistent poor control

●● The medication found in step 4; and

●● SABA when required; and

●● inhaled corticosteroid dose (may be moved to the upper end of the standard dose range if required); and ●● LABA. If the patient has no response to this, then stop and add one of the following: ●● Leukotriene receptor antagonist (LRA) ●● modified-release (MR) oral theophylline ●● MR oral beta 2 agonist.

Step 2

Oral steroid addition

●● Inhaled corticosteroid; and ●● LABA. A six-week trial of one

●● regular oral prednisolone (patient may require specialist care).

or more of the following should also be trialled: ●● LRA ●● MR oral theophylline ●● MR oral beta 2 agonist

Step 3

Step 4

If patients prescribed theophylline are also long-term smokers or regularly consume alcohol, the concentration of the drug in the body will be lower than those who do not. This means the dose may need to be adjusted accordingly. In addition, when used at normal doses in combination with a SABA, it may cause hypokalaemia – with symptoms including elevated blood pressure, muscle weakness, myalgia and tremor. Aminophylline is a stable mixture of theophylline and ethylenediamine – which has greater solubility in water than theophylline. It is given by injection to relieve cases of severe acute asthma, but is rarely seen in the community setting.

Step 5

surrounding the airways, and contract when triggered. Antimuscarinics prevent this trigger – and therefore airway muscle contraction – from occurring, providing short-term relief from chronic asthma exacerbations. The use of antimuscarinics for asthma is limited, and they are usually reserved for patients suffering from chronic obstructive pulmonary disease.

Oral corticosteroids Prednisolone is often prescribed for chronic asthma that can not be controlled by inhaled medication. However, the aim should be to move the patient from oral steroids to inhaled steroid use, as oral steroids have more pronounced side effects.

Antimuscarinics

Chronic asthma management

Muscarinic receptors exist in the muscles

The British Thoracic Society and Scottish

Take the 5-minute test 1. Short-acting beta 2 agonists have a duration of action of six to eight hours. True or false?

6. Leukotriene receptor antagonists are more effective at reducing inflammation than inhaled corticosteroids. True or false?

2. Paradoxical bronchospasm is a rare, but serious, side effect of short-acting beta 2 agonists. True or false?

7. Theophylline, if used in combination with a short-acting beta 2 agonist, can cause hypokalemia. True or false?

3. Side effects of long-acting beta 2 agonists include joint pain, dizziness and nausea. True or false?

8. Reducing the dose of inhaled corticosteroid needs to be done slowly, with a dose reduction of 50% every three months. True or false?

4. In smokers, the effectiveness of inhaled corticosteroids may be decreased. True or false?

9. Dry powder inhalers require less co-ordination to use than metered dose inhalers. True or false?

5. The Clenil Modulite inhaler releases extra-fine particles, making it almost twice as potent as other beclometasonecontaining inhalers. True or false?

10. When using a spacer device, tidal breathing is not as effective as single breaths. True or false?

17.09.2016 Chemist+Druggist 15

UPDATE Clinical chemistanddruggist.co.uk

Intercollegiate Guidelines Network guidelines on asthma management are used to determine the different stages of asthma treatment (see diagram on previous page).

Optimising treatment It is important that a patient is on the correct medicine to ensure optimum treatment while minimising side effects. There are several factors you should consider: ●●Medication should be reviewed every three months and if control is achieved, then a reduction is possible. If a patient’s dose of inhaled corticosteroid is being reduced, it needs to be done slowly – a reduction of 50% every three months is recommended ●●However, if the patient is using their reliever inhaler more than twice a week, or is experiencing night-time symptoms, they may need to increase their corticosteroid dose ●●If a patient is using a peak flow meter to measure their lung activity, then they can be given directions about dose adjustments – within specified limits – that they can make themselves.

Asthma in pregnancy It is always important to control asthma, but it is particularly important during pregnancy. When chronic asthma is controlled, it helps prevent complications throughout pregnancy, including during labour and foetal development. If a pregnant patient has an acute exacerbation of asthma, you should refer them promptly to hospital for treatment. They may be given nebulised treatments, as well as oxygen and perhaps oral prednisolone (as little of the drug will reach the foetus).

Types of inhaler device There are a variety of inhaler devices available. Ensuring patients understand how to use these correctly improves compliance and makes the medication more likely to work. Whatever device is prescribed, you should ensure the patient is familiar with the technique required to optimise delivery and check this technique regularly. The two most commonly prescribed devices are: ●●Metered dose inhalers (MDI) are handheld devices that deliver a specific amount of medication in aerosol form. Their use requires a level of coordination and dexterity – often a barrier to patient use. Good inhaler technique is imperative to the success of this type of inhaler and must be clearly explained and demonstrated. Patients with arthritis may struggle to activate an MDI – recommending compliance tools, such as an inhalation aid, can help these individuals. ●●Dry powder inhalers (DPI) come in the form of a small handheld device that uses a dry powder to deliver medication. This style of inhaler requires less coordination – relying on the patient’s peak inhaled flow rate 16 Chemist+Druggist 17.09.2016

Spacer devices Spacer devices work by slowing down drug particle speed while simultaneously maintaining the drug in suspension, making coordination of actuation and inhalation much less critical when using metered dose inhalers (MDIs). By minimising error during inhalation, patients receive the appropriate dose to their airways. Studies have shown that large-volume or small-volume spacers used in combination with MDIs deposit more of the drug in the lungs and less in the throat. Benefits from the use of spacers include: ●● better pattern of drug deposition means a reduction in side effects ●● ease of use, especially by children and the elderly (except those with weak or arthritic hands) ●● they can be as effective as a nebuliser in the treatment of acute attacks ●● they are light, cheap, maintenance-free, portable and available on prescription ●● they are useful for first-time users. When dispensing spacers, you should ensure the device is compatible with the inhaler being used and that the patient understands: ●● the drug should be administered by repeated single actuations of the MDI into the spacer, each followed by inhalation ●● there should be minimal delay between actuation and inhalation, with no more

instead – and is commonly given to children. Sometimes it can be difficult to tell if inhalers are empty – as not all devices have counters – or even if the dose has been inhaled. Consequently, some patients may find themselves taking more medication than required or discarding the devices before they are completely empty.

than 30 seconds elapsing before breathing in the contents of the spacer – this is because the drug aerosol is short-lived ●● tidal (normal) breathing is as effective as taking a single breath. Some patients may complain of a cough after using a spacer and MDI – the reasons behind this are poorly understood.

Cleaning a spacer These devices should be regularly cleaned, as per the manufacturer’s instructions, so that their performance is not adversely affected. An accumulation of electrostatic charge within the spacer can increase drug absorption onto the plastic. Patients should read the leaflets that come with their device, but the following advice can be generally recommended: ●● remove the inhaler from the spacer when it appears ‘dusty’ ●● rinse the spacer in warm soapy water and then rinse again with fresh water – do not scrub ●● shake and stand upright to allow water to drain away and leave to air-dry – do not dry with a cloth as this can cause a build-up of static ●● clean the spacer monthly, rather than weekly, or refer to the manufacturer’s recommendations ●● request a new spacer every six to 12 months, depending on frequency of use.

To help avoid this, you may want to calculate how long their inhaler will last if used as directed – this enables patients to predict when they will need a new one. This may be more difficult for inhalers that are used when required, such as relievers. However, it may still help patients identify if they are using the device too much and may need to see their prescriber.

Asthma treatment CPD Reflect What are the side effects of

Read the MUR tips for inhaled

long-acting beta 2 agonists? How can

corticosteroids on the C+D website at

oral thrush be reduced in patients using

tinyurl.com/asthma24

inhaled corticosteroids? How should spacer devices be cleaned?

Find out more about inhalers on the Asthma UK website at tinyurl.com/asthma27

Plan This article contains information about the management of asthma

Read the previous C+D Update article

including the treatments available for

Asthma causes and symptoms, C+D,

preventing asthma and relieving flare-ups.

September 3, at tinyurl.com/AsthmaUpdate

Types of inhaler and advice for patients using a spacer device are also discussed.

Evaluate Are you now confident in your knowledge of the management of asthma?

Act Revise your knowledge of the

Could you give advice to patients about

medications available for asthma

inhaler technique?

management from the BNF Section 3