Metered Dose Inhaler (MDI)

A metered dose inhaler (MDI) is a pressurized canister that delivers a measured amount of medication to the lungs. MDIs are most often used to treat asthma, but are also prescribed for chronic obstructive pulmonary disease (COPD) and other lung disorders.

Metered-dose Inhaler (MDI)MDIs are useful because of their convenient small size (which makes them easy to carry anywhere) and ease of use. Simply pressing the MDI releases a spray of medication directly to the lung's airways, with no need to measure a dosage beforehand.

It is important to take your medicine as prescribed by your doctor or other health care professional and to use the proper technique to deliver the medicine to your lungs. If you don’t use your inhaler correctly, you won’t get the medicine you need.

Here are general steps for how to use and clean a metered-dose inhaler.

Be sure to read the instructions that come with your inhaler.

Ask your doctor, pharmacist, or other health care professional (such as nurse practitioner, physician assistant, nurse, respiratory therapist, or asthma educator) to show you how to use your inhaler.

Review your technique at each follow-up visit.

  • Take off cap. Shake the inhaler. Prime (spray or pump) the inhaler as needed according to manufacturer’s instructions (each brand is different).
  • If you use a spacer or valved holding chamber (VHC), remove the cap and look into the mouthpiece to make sure nothing is in it. Place the inhaler in the rubber ring on the end of the spacer/VHC.
  • Stand up or sit up straight.
  • Take a deep breath in. Tilt head back slightly and blow out completely to empty your lungs.
  • Place the mouthpiece of the inhaler or spacer/VHC in your mouth and close your lips around it to form a tight seal.
  • As you start to breathe in, press down firmly on the top of the medicine canister to release one “puff” of medicine. Breathe in slowly (gently) and as deeply as you can for 3 to 5 seconds.
  • Hold your breath and count to 10.
  • Take the inhaler or spacer/VHC out of your mouth. Breathe out slowly.
  • If you are supposed to take 2 puffs of medicine per dose, wait 1 minute and repeat steps 3 through 8.
  • If using an inhaled corticosteroid, rinse out your mouth with water and spit it out. Rinsing will help to prevent an infection in the mouth.

How to Clean a Metered-Dose Inhaler and Spacer

Keep your inhaler and spacer/VHC clean so they can work properly. Read the manufacturer’s instructions and talk to your doctor, pharmacist, or other health care professional about how to clean your inhaler and spacer/VHC (each brand is different).

When cleaning your inhaler and spacer/VHC, remember:

  • Never put the medicine canister in water.
  • Never brush or wipe inside the spacer/VHC.

Source: National Heart, Lung & Blood Institute
Last updated : 5/11/2020

Metered Dose Inhaler (MDI) originally published by National Heart, Lung & Blood Institute

Asthma