
Preventers / Controllers
- Preventers control the swelling and inflammation in the airways, stopping them from being so sensitive and reducing the risk of severe attacks.
- Their effects build up over a period of time so they need to be taken every day, usually morning and evening, even when you are feeling well.
- You will be started on an appropriate level of treatment to get your symptoms under control; once this has been achieved the treatment will be reduced to the lowest possible dose.
- Preventer inhalers usually contain a low dose of steroid medication. There are several kinds of inhaled steroids, but they all work in the same way to reduce the inflammation in your airways.
- Combination inhalers contain an inhaled steroid and a long acting reliever medication in one device. Your doctor may prescribe a combination inhaler if your asthma is not controlled on an inhaled steroid alone.
When are preventers prescribed?
You should be prescribed a preventer if you:
- are breathless, cough or have a tight chest during everyday activities more than twice a week
- need to use your reliever inhaler more than twice a week
- have sleep disturbed by cough or chest tightness more than twice a month
- have bad attacks of breathlessness when you have a chest infection or are in a smoky atmosphere.
What will my preventer do for me?
As the protective effect of the steroid builds up, you will be less likely to have asthma attacks. You will be less likely to be breathless during the day and at night and you will not need to use your reliever inhaler as often.
Why is my reliever inhaler not enough?
Reliever inhalers relax your airways, which help breathlessness, but they do not treat airway inflammation. As well as the relaxing effect of a reliever inhaler, you need the anti-inflammatory effect of a preventer. Once airways are less inflamed they are less sensitive to triggers such as cigarette smoke and viral infections.
How long will it take to work?
It may take up to 14 days for your preventer medicine to reduce inflammation and mucus in your airways. For children, it could take 1-2 months.
Don't stop taking your preventer if you do not notice an improvement in the first few days. it if nothing much happens for a few days. Gradually, chest tightness, night cough and wheeze should become less. You should also notice that you need to use less reliever inhaler. You should continue to take your preventer every day, morning and evening even when you are feeling well. This is how you keep your asthma symptoms under control.
When should I see my doctor or asthma nurse again?
Your doctor or asthma nurse will probably want to see you within a month after you start using a preventer to review your symptoms. They will be able to adjust your medicines if your symptoms have not improved.
Do I really need to take my preventer every day?
Yes. To work properly, preventers need to be taken every day, usually morning and evening, even if you are feeling well. The protective effect of the preventer medicine builds up gradually.
Once this protection is working, occasionally forgetting to take your inhaler will usually not have bad effects. But forgetting or stopping for several days at a time will mean your protection begins to disappear.

