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How to Use a Metered-Dose Inhaler

Last Updated October 2023 | This article was created by familydoctor.org editorial staff and reviewed by Beth Oller, MD

A metered-dose inhaler is a small, hand-held device filled with medicine to treat breathing problems. It helps deliver a certain amount of medicine through your mouth and into your lungs. It is commonly used to treat breathing difficulties related to asthma, chronic obstructive pulmonary disease (COPD), and other respiratory problems.

Path to well being

Each inhaler consists of a small canister of medicine connected to a mouthpiece. The canister is pressurized. As you press down on the canister, it releases a mist of medicine. You breathe that mist into your lungs. It’s important to use your inhaler correctly. Otherwise, your airways will not receive the right amount of medicine. Read and follow all instructions that come with your inhaler.

Here are the steps to correctly use your inhaler:

  • Remove the cap and hold the inhaler upright.
  • If your doctor recommends, use a spacer (a hollow, plastic chamber) to filter the medicine between the inhaler and your mouth. The chamber protects your throat from irritation from the medicine. Note: Check your insurance plan as some may not cover spacers.
  • Stand or sit up straight.
  • Shake the inhaler.
  • Tilt your head back slightly and breathe out all the way.
  • Put the inhaler in your mouth.
  • Press down on the inhaler quickly to release the medicine as you start to breathe in slowly.
  • Breathe in slowly for 3 to 5 seconds.
  • Hold your breath for 10 seconds to allow medicine to go deeply into your lungs.
  • Breathe out slowly.
  • Repeat puffs as directed by your doctor. Wait 1 minute before taking the second puff.

Some inhalers (such as steroid inhalers) also recommend rinsing your mouth out with water and gargling with water (spit out the water) after use.

These instructions are for a metered-dose inhaler only. Inhaled dry-powder inhalers are used differently. To use a dry powder inhaler, close your mouth tightly around the mouthpiece and breathe in quickly.

Talk to your doctor if you have any questions about how to take your inhaler.

Things to consider

It’s important to keep track of how much medicine you’ve used so you can replace your inhaler before you run out of medicine. Many inhalers include a “counter” on the back that keeps track of how much medicine is left in the device. If your inhaler does not, you can use the following method to figure out when you’ll need to get a refill:

  • With a new inhaler, the canister will usually have the number of puffs available printed on the label. Divide the number of puffs in the canister by the number of puffs you take each day. The number you get will be the number of days the canister should last. For example, if you take 4 puffs each day from a 200-puff canister, you will need to have a new canister every 50 days.
  • Using a calendar, count forward that many days to see when your medicine will run out. Choose a day 2 days before this date to have your prescription refilled so you won’t run out of medicine.
  • With a permanent marker, write the refill date on the canister and on your calendar.
  • If you use your inhaler for rescue medicine (when you are struggling the most to breathe), ask your doctor if he or she will write a prescription for 2 inhalers. Rescue inhalers aren’t used regularly, so it will be difficult to plan a refill date. Get your prescription filled when the first inhaler is empty. This way, you’ll always have enough rescue medicine on hand.
  • Clean your inhaler regularly. Read the directions on your inhaler’s packaging. You also can ask your doctor to show you.


Questions for your doctor

  • Can you demonstrate how I should use my inhaler?
  • What happens if I breathe in too many puffs at one time?
  • When I use my inhaler, my heart races. Is that safe?
  • Why do my hands sometimes shake after I take my inhaler?
  • Why do I sometimes cough right after using my inhaler?
  • What should I do if I don’t have an inhaler but am having trouble breathing?
  • Is it okay to let others use my inhaler?
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