Commonly called preventers, inhaled corticosteroids (ICS) or single preventer inhalers, these inhalers contain just one medicine/drug. 

Includes medications such as Alvesco, Arnuity, Flixotide, Fluticasone Cipla, Pulmicort, Qvar. (See generic names here: Active Ingredients Guide for Asthma Medication). 


Preventers are the mainstay of asthma treatment because they treat the underlying cause of the symptoms. They contain a corticosteroid which works by making the airways less sensitive, reduce redness and swelling and help to dry up mucus.  

You need to take your preventer every day for it to work properly,  to prevent symptoms and reduce the likelihood of asthma attacks. It may take two to four weeks before they reach their full effect. Preventers have also been found to improve asthma-related quality of life. 

Combination preventers contain two or more medicines in one inhaler. They are the next step up in asthma treatment. Read more here: Combination Preventers 


Using your preventer properly is vital to get the medication to your lungs where it is needed. This is true no matter what type of inhaler you are using.  

To make sure you are using your preventer correctly see: 

It is extra important to use a spacer if your preventer is in a metered-dose inhaler device (puffer), as this will reduce the chance of side-effects.  

Rinse, gargle, and spit after use. This will reduce the risk of side effects in your mouth and throat. 


Most people should have a preventer prescribed to reduce their risk of asthma attacks. 

Preventer medication should be prescribed for most adults and adolescents with asthma. If you don’t have a preventer yet, talk to your doctor about it if you 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 requiring an urgent visit to a GP or emergency department in the past 12 months or needed a course of oral corticosteroids 

Preventer medication for children is determined by how often and how severe their asthma symptoms are. Discuss preventer medications with the GP if your child is experiencing: 

  • Symptoms which occur at least once per week and frequently disrupt child’s sleeping or play. 
  • Flare-ups are generally severe enough to need a visit to the Emergency Department or needed oral corticosteroids. 
  • The child has had a flare-up that needed hospitalisation or ICU. 
  • Symptoms or flare-ups occur at least 4-6 times weekly 

If you have been prescribed a preventer medication, you should take it every day, even if you feel well. Don’t stop taking it once you feel better, this is a sign that it is working! 


  •  sore throat 
  • hoarse voice 
  • oral thrush. 

You can reduce these by: 

  • Using a spacer with puffers 
  • Always rinse, gargle and spit after using preventer medication.  
  • Young children who cannot gargle and spit should have a drink of water.  

Speak to your doctor if you have any concerns about side effects