How Asthma Inhalers Work

Asthma inhalers work by allowing the drugs in them to get straight into the airways. For this reason, the amount of drug used by the inhaler is less than that used when the drug is taken in tablet or medicine form. The drugs used help the airways to stay open, making it easier to breathe. It also means that side effects are much less likely to occur.

There are three main types of drug inside asthma inhalers, and these are grouped into “Relievers”, “Preventers”, and “Long Acting Bronchodilators”.

Relievers

This type of inhaler is used immediately when the symptoms of asthma occur. For example, when the asthmatic feels breathless at a particular moment, this type of inhaler is used. The drug in this type of inhaler helps to relax the muscles in the airways, and the type of drug is called a bronchodilator. This type of reliever is used when the sufferer only has occasional symptoms: when the symptoms occur more than a few times per week, then a “Preventer” inhaler is usually recommended. There are several reliever drugs available such as terbutaline or salbutamol. The inhaler device for these drugs is often blue, green or grey.

Preventers

This type of inhaler is used every day to try to prevent asthma symptoms occuring. The drug administered is usually a steroid. These work by reducing inflammation in the airways, and making the airways wider, so that breathing is easier. It takes time for this type of inhaler to work, and it is of little use when the symptoms are already present. After about 10 days of use or even less, symptoms may have reduced significantly. After one or two months, this type of inhaler reaches maximum benefit, so that there is little if any use for a “Reliever” inhaler again. There are different types of device to administer “Preventer” drugs, but they tend to be red, brown or orange.

Long-Acting Bronchodilators

The drugs used in this type of inhaler work in a similar way to those used in “Reliever, but the effects last much longer. Using the drugs in this type of inhaler can give relief from symptoms for up to 12 hours. The drugs used are typically formeterol or salmeterol. This type of inhaler may be used to supplement the use of a “Preventer’ inhaler, if the symptoms are not totally relieved by the “Preventer”.

There are also several different types of inhaler. Pressurised (metered Dose) inhalers are the most common. These are pressurised so that the drug is dispensed at consistent volumes each time. They are small and convenient, although it is important to breathe at the same moment as the drug is dispensed. An inhaler with a spacer may be used for young children or babies, as this type of inhaler negates the need to “co-ordinate” the act of dispensing and breathing in the medication. Dry powder dispensers are available too, that do not need any pressure to transport the drug to the mouth. With this type of inhaler, the drug is sucked in a powder form. Finally, nebulisers are devices that make an aerosol vapour of the drug. A face mask needs to be used, and they are easy to use – the user just needs to breathe normally.

Note: Always contact the appropriate health care professional before using any of the drugs or dispensing devices mentioned.