Metered-dose inhalers

Be sure the inhaler has medicine in it before you use it. If you use the same dose every day, you can calculate how long it will last. For example, a canister that contains 200 doses will last 25 days at a dose of four puffs twice a day (200 doses ÷ 8 puffs per day = 25 days). Shaking the container or floating the inhaler in water are not good ways to tell if any medication is left. Stop using the inhaler after 200 doses, even if you can see a plume of mist, as it will not contain a sufficient amount of medicine. Always keep an extra inhaler handy so you are sure not to run out.

MDIs may not work properly if cold. If your MDI is exposed to cold weather, warm it between your hands before using it.

To be sure you are using your MDI correctly, stand in front of a mirror and follow the steps below. If fog comes from your mouth when inhaling or exhaling, the medication is not reaching your lungs.

The most common errors people make when using inhalers include:

• poor timing between releasing the medication and inhaling (for example, exhaling instead of inhaling at the moment the medication is released)
• inhaling too rapidly
• not holding your breath after inhaling the medication
• not keeping the inhaler clean

Once a year, have your doctor watch you use your inhaler to be sure you are doing it properly.

To prevent clogging, remove the metal canister and rinse your inhaler daily and keep the cap on the inhaler when not in use. Wash your inhaler once a week in warm soapy water, using mild dish soap.