Asthma Health Center

Metered Dose Inhalers for Asthma

How Do I Care for a Metered Dose Inhaler With an Aerochamber and Mask?

Clean the spacer chamber every other day. If you are not using it often, you may only need to clean it once a week. Let it air dry, and store it in a clean, dry place when you're not using it.

How Do I Know When a Metered Dose Inhaler Is Empty?

The number of puffs contained in your child's metered dose inhaler is printed on the side of the canister. After your child has used that number of puffs, you must discard the inhaler even if it continues to spray. Keep track of how many puffs your child has used.

If your child uses an MDI every day to control his or her asthma symptoms, you can determine how long it will last by dividing the total number of puffs in the MDI by the total puffs your child uses every day. For example, if your child's MDI has 200 puffs and he uses four puffs per day, divide 200 by four. In this case, your child's MDI would last 50 days. Using a calendar, count forward that many days to determine when to discard your child's MDI and begin using a new one.

If your child uses an inhaler only when he needs to, you must keep track of how many times your child sprays the inhaler. If you prefer, you can obtain a device that has a counter to count down the number of puffs each time your child presses the inhaler. Ask your child's doctor for more information on these devices. In general it is important to be aware of how many doses remain in the MDI. Even when the medication is depleted, the MDI can still release a spray of propellant that can be mistaken for a spray of medicine.