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Asthma Inhalers: The 3 Basic Types Explained

Types Of Asthma Inhalers

An asthma inhaler is a handheld device you use to treat your asthma. Asthma medications are either short-acting or long-acting. You use short-acting medications to stop an asthma attack, and take long-acting medications to control asthma and prevent attacks. Many of the most effective asthma medicines are inhaled into your lungs. An asthma inhaler is a safe and reliable way to get the right dose of medication into your lungs where you need it.

There are three basic types of asthma inhalers: metered-dose inhaler (MDI), dry powder inhaler (DPI), and soft mist inhaler (SMI)

Metered dose inhalers

The MDI is the most common type of asthma inhaler. It is a small pressurized canister that fits inside a plastic boot-shaped holder with an attached mouthpiece. The whole device fits easily in your hand or pocket. To release the medication, you simply push down on the canister into the boot, and the MDI releases only the amount of medicine you need.

With most MDIs, you have to breathe in when you press down on the canister. One new type of MDI releases medication automatically (without having to push down) when you inhale. The number of puffs you should take for each treatment will be listed in your treatment plan.

All MDIs list the number of puffs contained in the canister. For some MDIs, you may have to keep track of the puffs you take. Other MDIs come with a built-in counter. You can also buy a counter and attach it to your MDI to make it easier to keep track of how many you've used. After you have used the total number of puffs, you need a new canister.

There are many brands of MDI. Your doctor will show you how to use yours, and you can also refer to the specific instructions that come with your device. These are the basic steps for using an MDI:

  • Remove the cap from the MDI and shake it well.
  • Prime your device according to the instructions. For example, you may need to spray a few puffs into the air.
  • Breathe out completely.
  • Place the mouthpiece into your mouth and close your lips tightly.
  • Press down on the canister as you slowly start to inhale.
  • Breathe in as deeply as you can for 5 seconds.
  • Hold your breath for 10 seconds.
  • If you are instructed to take more than one puff, wait one minute and repeat the process.
  • Replace the cap.

To care for your MDI, remove the canister and rinse the plastic holder with warm water once each week and let it air dry. If your MDI is not removable from the canister, clean the mouthpiece with a cloth or cotton swab.

MDIs can also be used with a device called a holding chamber (sometimes called a spacer) between the canister and the mouthpiece. The medicine is released into the chamber when you trigger the device. A valve between the chamber and the mouthpiece makes it easier to inhale the medication. Some people find it easier to use a holding chamber with a MDI because you can take a long, deep breath more easily.

If you need to take a corticosteroid medicine through your inhaler, your doctor will probably suggest that you use a spacer. Some doctors recommend using an MDI with a spacer because it helps you get more medication into your lungs. Some spacers come attached to the MDI, or you can buy a spacer that attaches to your MDI.

Dry powder inhalers

DPIs are also small, handheld devices, but this type of inhaler contains only powdered medication. There is no pressurized canister. Some DPIs contain up to 200 doses. Others require you to load a single dose into the inhaler each time you use it, which can be difficult for some people.

A DPI is breath-activated and requires a fast, deep inhalation, which some people may find difficult to do. DPIs have a built-in counter that will let you know when you are getting low on medicine. One disadvantage of a DPI is that the powder may clump in high humidity.

There are several brands of DPI. Your doctor will show you how to use yours, and you can also refer to the specific instructions that come with your device. These are the basic steps for using a DPI:

  • Remove any cap on the inhaler.
  • If your DPI needs to be loaded, load it according to the instructions.
  • Hold the inhaler away from your mouth and breathe out as much air as you can.
  • Place the mouthpiece in your mouth and close your lips tightly.
  • Breathe in a strong steady breath for 2 to 3 seconds.
  • Remove the mouthpiece and hold your breath for 10 seconds.
  • Exhale slowly.
  • If you are instructed to take more than one puff, wait one minute and repeat the process.
  • If you are using a corticosteroid medication, wash your mouth and gargle with water or mouthwash after your treatment.

Keep your DPI in a dry place at room temperature. Don’t keep it in the bathroom. Keep water away from the DPI. Never shake it. Do not use a spacer with a DPI. Follow any other patient instructions for caring for your DPI.

Soft mist inhalers

A SMI is a handheld plastic device that releases a slow-moving mist when inhaled. This type of inhaler works well for reaching the small airways in your lungs.

An SMI has no propellant. The dose is spring-loaded, and the medicine is converted into a mist when you use it.

The inhaler has a dose indicator on the side of the device. When the indicator is in the red zone, you have about seven doses left.

To use an SMI:

  • Load the canister into the device according to the instructions.
  • Prime the device according to the instructions. You may need to prime the device several times before using it the first time, and you may need to prime it again if you have not used the device for a while.
  • Hold the inhaler upright, with the cap closed, and turn the canister base in the direction of the arrows on the label until you hear it click in place. This means a dose is loaded.
  • Breathe out away from the inhaler
  • Open the cap and close your lips around the mouthpiece. Breathe in slowly and deeply through your mouth while you press the dose release button.
  • Hold your breath for 5 to 10 seconds and breathe out slowly.

Follow your doctor's instructions on how many doses to take.

To clean your device, wipe the mouthpiece with a damp cloth at least once a week. Make sure you keep the cap closed when the device is not in use.

The bottom line

There are many options when it comes to asthma inhalers. All are effective treatments, but the best choice for you will depend on your particular situation. Some asthma medications only work in certain inhalers. You may also find that one type of inhaler is easier for you to use than another. Work with your doctor to get the type of inhaler that's best for you.

Article references

  1. Mayo Clinic, Asthma Inhalers: Which one’s right for you?
  2. Cleveland Clinic, Inhalers,
  3. Cleveland Clinic, Dry Powder Inhaler (DPI): Diskus,®
  4. Clinical Drug Investigation, The Respimat Soft Mist Inhaler, Implications of Drug Delivery Characteristics for Patients,
  5. National Jewish Health, Using a Respimat,