Using Anti-Asthmatic Inhalers
Using inhalers
The value of using an inhaler rather than taking tablets or syrup is explained on p. 141 for steroids. The same principle applies to all drugs.
The oldest type of inhaler is the ‘puffer’ or aerosol inhaler, properly called a ‘pressurised metered-dose inhaler’ or MDI. It delivers the drug as a fine, moist, spray. In addition, there are now many devices that deliver drugs in dry-powder form.
If you or your child find the aerosol inhalers difficult, you may do better with a dry-powder inhaler. Your doctor should have several different inhalers available for you to try out, to see which one suits you best.
When you are given an inhaler you must be shown how to use it by a doctor or asthma nurse. A great many asthma patients have a ‘poor inhaler technique’, and get too little of the drug as a result. This often leads to their asthma getting out of control. The advice given here for using inhalers is no substitute for proper training, and should only be used to supplement what your doctor or asthma nurse has told you.
When using an aerosol inhaler or MDI, remember to shake the inhaler well or you will not get the right dose. Your in-breath must coincide exactly with pressing the canister down: this is the part that many people find difficult. You must breathe in slowly and deeply, otherwise you do not get much of the drug into your airways.
Many asthmatics stop inhaling the moment the
spray from the aerosol inhaler hits the back of the
throat. The spray contains a propellant, which
makes it very cold, and there is a natural reflex
response to this cold liquid which stops inhalation.
This response may be impossible to control. If so,
you need a dry-powder inhaler (see right), or a
spacer to use with your aerosol inhaler (see p. 162).
Breath-operated aerosol inhalers such as the
Autohaler can be useful for those who find ordinary
aerosol inhalers too hard to use. With these devices, you do not have to push the canister down because your in-breath triggers the release of the drug. Take care not to block the air-intake holes with your hands and don’t stop breathing when you hear the inhaler click. (If there is no click, start again and breathe in more forcefully this time.)
One hazard with aerosol inhalers is that, when almost empty, they produce no drug – just the propellant. Although they still ‘puff’ normally, they are not effective. It may be hard to tell when your inhaler is running low. Ask your doctor or asthma nurse for advice about this.
Many asthmatics find dry-powder inhalers such as the Spinhaler, Rotahaler, Diskhaler, Accuhaler, Clickhaler and Turbohaler are the easiest to use. They have no aerosol device, so none of the problems associated with the coldness of the propellant.
On the other hand, nothing pushes the drug into your mouth and lungs with a dry-powder inhaler: you have to do all the work yourself. This means you have to breathe in quite hard and fast. During a severe asthma attack you may not be able to breathe in hard enough to get a good dose of the drug. Some asthmatics have an aerosol inhaler as well, often combined with a spacer (see p. 162), for use during severe attacks.
For the parents of asthmatics, who want to keep an eye on how much of a drug is being used, most of the dry-powder inhalers allow you to do so.
Arthritis and inhalers
Those who suffer from arthritis in their hands often find inhalers difficult to use. There are several aids now available to help with this problem – ask your doctor or asthma nurse about these.
Do hold your breath
Whichever type of inhaler you use, it is important to give the drugs a chance to do their work. After inhaling, and when your lungs are full, you should hold your breath for at least ten seconds. Then breathe out, but wait at least another 30 seconds before breathing in again.
Side effects from non-drug ingredients
There are other ingredients in inhalers, besides the drug, and they occasionally cause side effects.
Aerosol inhalers are the worst offenders. They can contain up to five non-drug ingredients, such as propellants and surfactants. Some asthmatics are sensitive to one of these, and respond with coughing or bronchospasm when they inhale them.
If inhaled in large amounts, the propellants in aerosol inhalers can give a mild ‘high’, and asthmatic teenagers and their friends may - very rarely - begin abusing inhaled beta-2 relievers. Parents should be alert for the possibility of such problems, but not worry unduly.
Dry-powder inhalers do not need propellants or surfactants, so they are suitable for anyone who develops a sensitivity to these. However, they may contain lactose, or milk sugar, in addition to the drug. Enough lactose is deposited in the mouth and swallowed to provoke symptoms, such as diarrhoea and wind, in people who suffer from severe lactose intolerance (see box on p. 79). Trace amounts of milk proteins in the lactose may be a problem for people with severe milk allergy.
CFCs and inhalers
Aerosol inhalers have long contained CFCs, which are very inert gases (at ground level) and perfectly safe to inhale. Unfortunately, they cause serious damage when they reach the ozone layer high above the earth, so they are being phased out in asthma inhalers, as they are in all aerosols. Other propellants, called hydrofluoroalkanes (HFAs), are being introduced to take their place. The spray from an HFA inhaler may taste and feel different, but it should do exactly the same job as a CFC inhaler: the drug it contains remains the same. Research suggests that these new propellants are very safe, but tell your doctor if your reaction to your inhaler seems to change suddenly.
These new propellants deliver medication more efficiently into the lungs, so that usually only half the previous dose is required. Unlike CFC-type inhalers, they will deliver a constant dose until empty. In addition, they are not affected as much by below-freezing temperatures.
Inhale - then clean your teeth
Asthmatic children are more prone to dental decay than other children, and inhalers are suspected of causing the problem. No one knows, as yet, exactly which ingredient of the inhalers is the culprit - it could be a drug, or a non-drug additive such as a propellant. Alternatively, the fact that the spray from some inhalers is slightly acidic could explain this side effect. Brushing the teeth after using the inhaler, or just rinsing out the mouth with water, is recommended as a preventive measure.
Using spacers
A spacer is a large empty chamber that can be fitted to an aerosol inhaler (a puffer or MIDI). to make it more effective and easier to use. The aerosol spray goes into one end of the spacer, and the asthmatic breathes it in from the other end.
When using a spacer, you can breathe normally: you don’t have to take all the drug in at once. or hold your breath after you’ve inhaled. But you should try to breathe as deeply as possible, and hold your breath for up to ten seconds if you can.
Note that spacers are for use with aerosol inhalers only. Spacers allow the aerosol propellant (see p. 161) to evaporate, leaving tiny airborne droplets of the drug to be inhaled. Once the propellant has evaporated, these droplets are no longer cold, so the reflex response that stops inhalation is avoided.
During an asthma attack, spacers are immensely valuable because they allow you to get some of the drug into your airways even though you are unable to take a deep breath. There is a collapsible spacer, called the E-Z Spacer, which folds up into a plastic case small enough to be slipped into a pocket. In a severe asthma attack, having such a spacer could save your life.
In an emergency, if no spacer is available, you can improvise one (see p. 100).
Babies and small children, who cannot yet coordinate the in-breath with pushing the aerosol canister down, need spacers for everyday use. There are spacers designed for children under two years, with masks that fit over the nose and mouth.
When using a spacer, shake the inhaler and then spray it into the spacer once only. Inhale within five seconds. During an asthma attack, you can add another dose from the inhaler every ten seconds, until the attack begins to subside, but keep a count of how many puffs you use (see p. 100).
For a young child, shake the inhaler well, and fit it to the spacer. Put the mouthpiece into the child’s mouth, or put the mask on. Tell the child to breathe in and out steadily. Listen for the clicking of the valve on the spacer - this shows that it is opening and closing. When the child’s breathing is regular, puff a single dose into the spacer. The child should breathe in and out 5-8 times.
Priming a spacer
Prime a new spacer, or one that has been washed, by firing the inhaler into it about five times. Do this before you actually need to use the spacer.
The drug will coat the spacer walls, due to an electrostatic charge on the plastic. You won’t be able to see the drug as it forms a very thin coating.
When you come to use the spacer, no more of the drug will stick to the spacer walls, because they are already coated, so the full dose will be available for you or your child to inhale.
Priming new spacers is particularly important when the asthmatic is a young child, because there may be some delay between firing the inhaler and the child actually getting a proper lungful of the drug. The longer the delay, the more chance the drug has to stick to the unprimed spacer walls.
A spacer can be used on a baby while it is asleep, which may make life easier for you both. If you need to use the spacer while the baby or toddler is awake, stroke the mask against the child’s cheek first. Keep smiling and talking so that the situation doesn’t seem so frightening. If the baby does start to cry, keep the mask in place: crying will bring on a deep in-breath which is just what is needed.
For an older child, decorating the spacer with coloured stickers can make it appear less daunting. Try to make using the spacer seem like a game. If this fails, don’t get into a battle with the child – leave it a while and try again later.
Playing with the spacer when feeling well will help the child to see it as something familiar, not as a frightening piece of equipment associated with asthma attacks.
Nebulisers
A nebuliser delivers high doses of asthma drugs in an easily inhaled form. It is generally used for severe asthma only, or in an emergency to relieve asthma attacks.
A nebuliser can be attached to an oxygen cylinder, which enriches the air–drug mixture with oxygen. This is useful in severe asthma.
The only people who need to have a nebuliser at home for emergencies are those with brittle asthma, whose condition can deteriorate very suddenly and sharply.
For routine use, only a very small minority of asthmatics require a nebuliser. They include:
• Those with such severe asthma that they depend on large doses of drugs to control their symptoms
• Very small children or elderly people with severe asthma, who have difficulty using inhalers. For them, a nebuliser may be the easiest way to take their drugs.
The fact that the hospital’s nebuliser is so effective in an emergency gives it a special mystique for many people, who assume that nebulisers are a magical cure for asthma. Nebulisers are widely advertised in specialist publications for asthmatics and, while they are expensive, they can look like the answer to a prayer. Many asthmatics, or their parents, mistakenly believe that owning a nebuliser would be the answer to all their problems. In fact the nebuliser only works so well because it delivers a much higher dose of the reliever drug – a dose which also carries a higher risk of side effects. This high-dose treatment should not be used on a regular basis unless it is absolutely essential. No one should buy a nebuliser without first discussing the matter with their doctor.
Asthmatics who own a nebuliser should have detailed written instructions from a doctor about when and how to use it, and how much of the drug to put in. One hazard of owning a nebuliser is that it may give you a false sense of security during emergencies, and delay you from getting expert medical help when you need it. If the nebuliser is for emergency use you should be told the exact signs that indicate a need to use it and – no less important – the signs that show the attack is out of control and needs hospital treatment.
Take care, when using a nebuliser, not to allow the mist to escape and settle on the face or eyes. Regular exposure to steroid mist can cause cataracts in the eyes, and thinning of the skin on the face. Anti-cholinergics (see p. 156) can cause glaucoma if they come into contact with the eye. The mask must fit very tightly. As an additional precaution, place a scarf around the upper edge of the mask to cover any gaps. Wash the face after using the nebuliser for steroids.
Keep off the cough mixture
Coughing can be a useful reaction in asthma, evicting mucus from the lungs. But in some asthmatics the cough does not produce mucus and seems to be no more than a reflex reaction to the airway inflammation. This type of cough can be debilitating, but it is not a good idea to treat it with cough mixture which has no benefit and may mask the seriousness of the asthma. Tackling the airway inflammation with preventer drugs such as steroids is the best course. Simple expectorants, which loosen mucus, may be of value – ask your pharmacist about these.