Other names: inhaled corticosteroids (ICS) or single preventer inhalers.  

They contain just one corticosteroid medicine.  

Includes medicines such as Alvesco, Arnuity, Flixotide, Fluticasone Cipla, Pulmicort, Qvar. (See list of  Active Ingredients Guide for Asthma Medication). 


Preventers play a vital part in your asthma treatment. Preventers contain a corticosteroid which makes the airways less sensitive, reduces redness and swelling and helps to dry up mucus.   

When you are prescribed a corticosteroid for asthma, your doctor is trying to copy the action of steroids that your body produces naturally to help reduce injury or inflammation.  


  • help to treat the underlying cause of the symptoms and 
  • work by treating the inside of airways to help keep them clear. 

Most adults and some kids with asthma should be prescribed a preventer. Ask your doctor about preventers if you don’t have one. Some clear signs you need one are if you have:  

  • experienced asthma symptoms at least once per week  
  • symptoms that cause regular trouble with activities   
  • 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  
  • needed a course oforal corticosteroids.  

If taken properly a preventer can: 

  • prevent symptoms 
  • reduce the likelihood of asthma attacks and 
  • improve asthma related quality of life.  

If you have been prescribed a preventer medicine, you should take it every day as directed, even if you no longer have asthma symptoms and feel well.  

Don’t stop taking it once you feel better, this is a sign that it is working!   

It may take two to four weeks of regular use before your preventer medicine reaches its full effect.


Remember to lower the chance of side effects gargle, rinse and spit after using your preventer inhaler. For small children, offer a drink of water if they cannot manage to gargle, rinse and spit. Clean teeth BEFORE using a preventer, then rinse mouth as above to maintain good oral health. 

Side effects of preventers may include:

  • Hoarse voice
  • Sore throat
  • Oral/mouth thursh (sore, yellowish raised patches in the mouth)
  • Irritated tongue
  • Coughing