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How to use your metered dose inhaler


Using a metered-dose inhaler (MDI) seems simple, but most patients do not use it the right way. When you use your MDI the wrong way, less medicine gets to your lungs. (Note: Dry powder inhalers require different instructions.)

Getting ready

  • Take off the cap and shake the inhaler hard.
  • Breathe out all the way.
  • Hold the inhaler 1 - 2 inches in front of your mouth (about the width of two fingers). Alternatively, place the MDI into a spacer and insert the spacer into your mouth.

Breathe in slowly

  • Start breathing in slowly through your mouth, and then press down on the inhaler one time. (If you use a spacer, first press down on the inhaler. Within 5 seconds, begin to breathe in slowly.)
  • Keep breathing in slowly, as deeply as you can.

Hold your breath

  • Hold your breath as you count to 10 slowly, if you can. This lets the medicine reach deep into your lungs.
  • For inhaled quick-relief medicine (beta-agonists), wait about 1 minute between puffs. There is no need to wait between puffs for other medicines.
  • Rinse your mouth afterward, to help reduce unwanted side effects.

Clean your inhaler as needed

Look at the hole where the medicine sprays out from your inhaler. If you see powder in or around the hole, clean the inhaler. Remove the metal canister from the L-shaped plastic mouthpiece. Rinse only the mouthpiece and cap in warm water. Let them dry overnight. In the morning, put the canister back inside. Put the cap on.

Know when to replace your inhaler

For control medicines you take each day, write the date you need to replace it on the canister.

For example, say your new canister has 200 puffs (number of puffs is listed on canister) and you are told to take 8 puffs per day. This canister will last 25 days. If you started using this inhaler on May 1, replace it on or before May 25. Write the date on your canister.

Do NOT put your canister in water to see if it is empty. This does not work.


Take Action!

Don't forget to bring your inhaler with you to medical appointments, so your doctor can make sure you are still using it correctly.


Created by the National Heart, Lung, and Blood Institute. Modified by A.D.A.M., Inc.