Asthma Health Center

Diseases affecting the lungs-such as asthma, emphysema, chronic bronchitis, and chronic obstructive pulmonary disease (COPD)-share many of the same medicines. These medicines are often delivered through a metered-dose inhaler (MDI).

Key points

Using an MDI:

• Delivers most of a measured dose of medicine directly to your lungs.
• Can help keep your symptoms under control and minimize long-term damage to your lungs.
• May prevent or reduce side effects of the medicine.
• May let you use less medicine than is found in a pill but get the same effect.
• May result in the medicine working faster than a pill form.

A metered-dose inhaler (MDI) is a handheld device that delivers a measured dose of medicine directly to your lungs. The medicine is usually in an aerosol form.

Using a spacer with an MDI is the most efficient way to get the most medicine to your lungs. A spacer functions as a "holding" area for the medicine before you inhale. Using a spacer with your MDI can improve the delivery of the medicine and help you if you have problems with releasing the medicine as you inhale. It might help to practice using the MDI and spacer in front of the mirror. A spacer should always be used with inhaled corticosteroids to avoid side effects.

An MDI can be used to give different types of medicine. The type of medicine in your inhaler will depend on what type of medicine you need to treat your specific condition. For example, the inhaler may contain a medicine to prevent an asthma attack or medicine to help relieve the symptoms of COPD.

For some medicines, you may need a certain type of MDI. Always check with your doctor and pharmacist when getting a new MDI.

Using a metered-dose inhaler (MDI) is beneficial because:

• It provides a puff of medicine in an accurate, measured dose.
• It can help keep your symptoms under control and minimize long-term damage to your lungs.
• When an MDI is used effectively, most of the medicine is delivered directly to your lungs and does not travel throughout the body. This may prevent or decrease side effects in the rest of your body.
• You may be able to use less medicine than is found in a pill but get the same effect.
• The medicine may work faster than a pill.

To get started using your metered-dose inhaler (MDI):

1. Talk with your doctor to be sure that you are using your MDI correctly. It might help if you practice using it in front of a mirror. Use the inhaler exactly as your doctor has prescribed.
2. Check that you have the correct medicine. If you use several inhalers, put a label on each one so that you know which one to use at the right time.
3. Check how much medicine is in the inhaler. Check the label of your inhaler medicine to see how many inhalations should be in the canister. If you know how many breaths you can take, you can replace your inhaler before you run out. Learn how to test your canister to estimate how much medicine is left. Your doctor or pharmacist can help you with this.
4. Use a spacer if you have problems getting the correct timing when you use an inhaler or if you are using corticosteroids.

Using a spacer with an MDI is the most efficient way to get the most medicine to your lungs.

View a slideshow on the correct way for a child to use an MDI with a spacer .

View a slideshow on the correct way for an adult to use an MDI with a spacer .

Although using an MDI with a spacer is usually recommended, you can also use an MDI without a spacer.

View a slideshow on the correct way for an adult or child to use an MDI without a spacer .

If you are using a corticosteroid inhaler, rinse your mouth out with water after use. Do not swallow the water. Swallowing the water will increase the chance that the medicine will get into your bloodstream. This may increase the side effects of the medicine.

Some powder may build up on the inhaler, but you may not need to clean the inhaler every day. Follow the directions for how and how often to clean the type of MDI you have.

Now that you have read this information, you are ready to start using a metered-dose inhaler.

Talk with your doctor

If you have questions about this information, take it with you when you visit your doctor.