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Asthma: Ways to Take Inhaled Medicines

British Columbia Specific Information

Asthma is a common chronic condition that causes your airway to narrow and swell. You may experience symptoms such as shortness of breath, tightness in the chest, coughing, and wheezing. Symptoms may range from being mildly annoying to deadly. For this reason it is important to speak with a health care provider if you think you may have asthma.

For more information about asthma, visit our Asthma Health Feature. You may also call 8-1-1 to speak with a registered nurse 24 hours a day, 7 days a week.​


When you use inhaled asthma medicine, you usually use a device that delivers the medicine directly to your lungs. Different types of delivery systems are available. And one type may be better for certain people or age groups or certain medicines.

Here are the different types of devices and some things to think about for each type.

Metered-dose inhaler (MDI)

This device is for adults and children.

  • Doctors recommend using a spacer with an MDI. The spacer is attached to the MDI. For children, a spacer may deliver the medicine to the lungs better than an inhaler alone. And for many people, a spacer is easier to use than an MDI alone. Using a spacer with an inhaled corticosteroid medicine can help reduce the medicine's side effects. It can also help you use less oral corticosteroid medicine.
  • A spacer is recommended for children age 5 and older.
  • A spacer and a face mask are recommended for children younger than 5.
  • Using a spacer with an MDI may work just as well and cost less than a nebulizer. It can also reduce the risk of an overdose.
  • If you don't use a spacer, you need to trigger a puff of medicine and inhale at the same time.

Dry powder inhaler (DPI)

This device is for children 4 years and older and adults.

  • How well the DPI works may depend on how well you breathe in.
  • Your doctor decides the amount of medicine you use based on how much air you can breathe in. It also may be different from the amount used in some MDIs.
  • DPIs may be easy to use, but they may be hard to use during an asthma attack. That's because you need to be able to breathe well to get the best effect.


This device is for people of any age who cannot use an MDI with a spacer.

  • A nebulizer uses a face mask or mouthpiece to deliver the medicine.
  • The medicine can be given over a period of 10 to 15 minutes.
  • Nebulizers may be helpful for those who are ill, who have serious difficulty breathing, or who have trouble using an inhaler. This includes infants, very young children, and older adults.
  • A nebulizer is not very precise in delivering medicine. There is a risk of getting too much medicine (overdose).
  • A nebulizer needs electricity to turn the medicine into a fine mist. Some nebulizers have a large compressor that does this. Other ones are portable and come with batteries.

Soft mist inhaler (SMI)

This device is for children 6 years and older and adults.

  • An SMI releases the medicine in a fine mist. The medicine comes out slowly and lasts longer in the air than the medicine in an MDI.
  • An SMI has a dose counter, so you can see how many doses you have left to use. The device will lock itself after all the medicine has been used.
  • You do not need to shake the SMI before using.


Current as of: November 14, 2022

Author: Healthwise Staff
Medical Review:
E. Gregory Thompson MD - Internal Medicine
Adam Husney MD - Family Medicine
Martin J. Gabica MD - Family Medicine