How to Use a Metered Dose Inhaler (Cleveland Clinic)

Inhaled respiratory medications are often taken by using a device called a metered dose inhaler, or MDI. The MDI is a pressurized canister of medicine in a plastic holder with a mouthpiece. When sprayed, it gives a reliable, consistent dose of medication.

There are two methods for using an MDI. In many cases, the preferred method is with a device called a valved holding chamber (figure 1). These devices attach to the MDI and hold the "spray" of medication. They make it easier to use the MDI and help get the medication into the lungs better. An MDI can also be used without a chamber (figure 2). These methods are described below. Your health care professional will decide which method is most appropriate for you.

Priming: Priming (spraying one or more puffs into the air before use) assures that the inhaler is ready to use and will dispense the correct amount of medication. Priming varies between devices, so it is important to read the patient instructions that come with your medication.

Using an MDI with a valved holding chamber (figure 1)

1. Remove the cap from the MDI and chamber. Shake well.
2. Insert the MDI into the open end of the chamber (opposite the mouthpiece).
3. Breathe out completely.
4. Place the mouthpiece of the chamber between your teeth and seal your lips tightly around it.
5. Press the canister once.
6. Breathe in slowly and completely through your mouth. If you hear a "horn-like" sound, you are breathing too quickly and need to slow down.
7. Hold your breath for 10 seconds (count to 10 slowly) to allow the medication to reach the airways of the lung.
8. Repeat the above steps for each puff ordered by your doctor. Wait about 1 minute in between puffs.
9. Replace the cap on your MDI when finished.
10. If you are using a corticosteroid MDI, rinse your mouth and gargle using water or mouthwash after each use. You should always use a chamber with a steroid MDI.

Using an MDI without a chamber (figure 2)

1. Remove the cap from the MDI and shake well.
2. Breathe out all the way.
3. Place the mouthpiece of the inhaler between your teeth and seal your lips tightly around it.
4. As you start to breathe in slowly, press down on the canister one time.
5. Keep breathing in as slowly and deeply as you can. (It should take about 5 to 7 seconds for you to completely breathe in.)
6. Hold your breath for 10 seconds (count to 10 slowly) to allow the medication to reach the airways of the lung.
7. Repeat the above steps for each puff ordered by your doctor. Wait about 1 minute between puffs.
8. Replace the cap on the MDI when finished.
9. If you are using a corticosteroid MDI, you should use a valved holding chamber as described above.