Last updated on 17/04/2020

The importance of using your Preventer medication

It is important to take your Preventer every day as prescribed, even if you feel well. Preventer medication is the key to staying well with asthma.

What do Preventers do?

Preventer medicines make the airways less sensitive, reduce redness and swelling and help to dry up mucus. They are the mainstay of asthma treatment because they treat the underlying cause of the symptoms. Preventers need to be taken every day to prevent symptoms and reduce the likelihood of asthma attacks and flare-ups.

Did you know: It may take two-four weeks before they reach their full effect, and occasionally up to 12 weeks.

Asthma can be well controlled with the appropriate medication in most people. The main types of medication are:

  • Inhaled corticosteroid Preventers that make the airways less sensitive to triggers by reducing swelling and mucus inside the airways – these are taken daily as indicated in your written Asthma Action Plan.
  • Inhaled corticosteroid and long-acting reliever combination Preventers containing two medications, both aiming to control symptoms
  • Short-acting relievers that act quickly to relax the tight muscles around the airways – this is the medication used during an asthma attack or flare-up or to treat symptoms.

Our medications and devices webpage can provide more information about medications and delivery techniques.

Preventer asthma medication

Preventer medication is usually a twice daily, a low dose of inhaled corticosteroid. Most adults and children can achieve good control of asthma symptoms with a low dose of inhaled corticosteroid. Inhaled corticosteroid reduces swelling and mucus in the airways and reduces your risk of severe asthma symptoms or flare-ups.

When is Preventer medication usually prescribed?

Preventer medication is recommended for most adults and adolescents with asthma when they have:

  • experienced asthma symptoms twice or more during the past month, or
  • been woken at night due to asthma symptoms once or more during the past month
  • had a flare-up in the past 12 months

Preventer medication for children is determined on how often and how severe their asthma symptoms are. Preventer medication is often considered when your child is experiencing:

  • Symptoms that occur regularly and/or frequently disrupt child’s sleeping or play.
  • Flare-ups are generally severe enough to require a visit to the Emergency Department or requires oral corticosteroids.
  • The child has had a flare-up that required hospitalisation or ICU (Intensive Care Unit).

If you or your child are not taking a Preventer, discuss the possibility of Preventer medication at your next asthma review appointment.

Persons with asthma should not change their treatment without talking to their doctor and having any changes listed on their written Asthma Action Plan.

What does good asthma control look like?

Most people with asthma can achieve good asthma control. This means that they:

  • Experience no limitations on your activities due to asthma
  • Have asthma symptoms on no more than two days a week
  • Need your blue/grey reliever no more than two days a week, or even not at all
  • Don’t get any asthma symptoms at night or when you wake up

Even if you think you are in control of your asthma, ask yourself, “Am I needing my reliever more than 2 days a week?” If the answer is yes, your asthma might be controlling you.

Take the Asthma Control Test today to determine your level of asthma control and see your GP for an asthma review.

Learn more about Asthma Preventers here.



National Asthma Council Australia. Australian Asthma Handbook, Version 2.0. National Asthma Council Australia, Melbourne, 2019. Website. Available from: