Metered-Dose Inhaler (MDI)

About a Metered-Dose Inhaler (MDI)

It is important to use a metered-dose inhaler correctly to get the full dosage and benefit from the medicine. Using the MDI correctly means the medication has a better chance to reach the small airways, which increases the medication's effectiveness. Using a good technique can also help reduce the side effects of medications. The following steps outline the best method to take an MDI without using a spacer attachment.

Why to Use the  MDI Correctly

The metered dose inhaler (MDI) consists of a pressurized canister of medication in a plastic case with a mouthpiece. Pressing the MDI releases a mist of medication. Its portable size, efficiency and convenience make the MDI a desirable method for inhalation treatment.

Steps For Using an MDI

1. Remove the cap from the inhaler.
2. Hold the inhaler with the mouthpiece at the bottom.
3. Shake the inhaler. This mixes the medication properly.
4. Check the box with the technique your health care provider recommends and follow the step:
   1. Use a spacer/holding chamber – Place the MDI in the spacer holding chamber. Seal your lips around the spacer/holding chamber mouthpiece.
   2. Use open mouth technique - Hold the mouthpiece 1½ - 2 inches (2 - 3 finger widths) in front of your mouth.
   3. Use closed mouth technique – Place the mouthpiece in your mouth with your lips sealed tightly around the mouthpiece.
5. Tilt your head back slightly and open your mouth wide.
6. Gently breathe out.
7. Press the inhaler and at the same time begin a slow, deep breath. Continue to breathe in slowly and deeply over 3 - 5 seconds. Breathing slowly delivers the medication deeply into the airways.
8. Hold your breath for up to ten seconds. This allows the medication time to deposit in the airways.
9. Resume normal breathing.
10. Repeat steps 3 - 9 when more than one puff is prescribed.

Clean the plastic case and cap by rinsing thoroughly with warm water, weekly.

MDI with Spacer

Your doctor may suggest that you use a metered-dose inhaler with a spacer. Read more about how a metered-dose inhaler with spacer can be an effective delivery method.

Breath-Activated Medication

The breath-activated metered-dose inhaler releases a mist of medicine when a person inhales. This type of inhaler has less propellant than a metered-dose inhaler. To use this inhaler, place the mouthpiece in your mouth and seal your lips around it. Breathe in deeply with a steady amount of moderate force.

Read more about Autohaler®, a type of breath-activated MDI.

 Hydrofluoroalkane (HFA) Propellant 

Many metered-dose inhalers have started using HFA's instead of chlorofluorocarbons (CFC's) as the propellants for the asthma medication. Find out how inhalers using HFA differ from others and how to adjust to your new products.

This information has been reviewed and approved by Ann Mullen, RN, CNS, MSN, AE-C (December 2014)