Metered-Dose Inhalers (MDI): How to Use

Teen Version

The metered-dose inhaler (MDI) is a container of medicine that releases a mist or powder of medicine. You inhale the medicine into the airways of your lungs. Inhaled asthma medicines contain a gas that helps the medicine get into your lungs. Chlorofluorocarbon (CFC) depletes the ozone layer in our atmosphere. It has been replaced by hydrofluoroalkane (HFA). The medicine in HFA inhalers is the same as the medicine in CFC inhalers. It's the gas used to push the medicine out of the inhaler that is changing. The HFA inhaler looks just like a CFC inhaler, but is a little different. The spray comes out with less force, is warmer, and has a slightly different taste. It is not felt as much in the throat when inhaled, but you still get the right amount of medicine.

The inhaler can be used alone, but it is highly recommended that you use a spacer attached to the MDI because it helps you get more medicine into your lungs.

Several different types or combinations of medicines are available as MDIs, including:

  • bronchodilators (albuterol, ProAir HFA, Proventil HFA, Ventolin HFA, or Maxair)
  • inhaled steroids (Flovent, Pulmicort, Qvar)
  • combination of long-acting bronchodilator and inhaled steroid (ADVAIR HFA, Symbicort)
  • cromolyn (Intal)
  • ipratropium bromide (Atrovent).

If you are using more than one type of MDI, you will usually use the bronchodilator first.

There are several ways to use an inhaler. If you are not using a spacer, the technique most often recommended is as follows:

  1. Shake the inhaler vigorously.
  2. If the MDI has not been used before or if the MDI has not been used for a while, you must then "prime" the MDI. Do this by spraying several sprays of the medicine into the air. Each time you use the MDI, the next dose is drawn into a chamber inside the MDI. If the MDI has not been used or sits for a long time without being used, some of the medicine leaks out of the holding area. This means you will not get the full dose of medicine the next time it is used. Priming the MDI makes sure that you get the full dose of the medicine.
  3. Hold the inhaler upright so the mouthpiece is at the bottom.
  4. Breathe out normally.
  5. For many inhalers the best way to get the medicine into your lungs is to open your mouth and hold the mouthpiece 1-and-1/2 to 2 inches in front of it (about 2 to 3 finger widths). This method decreases the amount of medicine that ends up in your mouth. It also helps medicine to reach your lungs rather than the back of the throat. However, the best way to use other types of inhalers is to place the MDI mouthpiece directly into your mouth and close your lips snugly around it. Talk with your provider or pharmacist about the best way to take the medicine that has been prescribed for you.
  6. Press the inhaler down once so it releases a spray of medicine into your mouth while you breathe in slowly. (One spray is called a puff.)
  7. Continue breathing in as slowly and deeply as possible.
  8. Hold your breath for 10 seconds or as long as is comfortable (this gives the medicine time to reach your airways).
  9. Breathe out slowly.
  10. After taking a few normal breaths, repeat steps 1 through 8 for another inhalation (puff) if required. Take the number of puffs prescribed by your healthcare provider.
  11. If you are taking an inhaled steroid medicine rinse your mouth and spit out the water after the last dose.
Written by the Asthma Task Force at The Children's Hospital, Denver.
Published by RelayHealth.
Last modified: 2009-02-06
Last reviewed: 2008-12-29
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
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