How to Prime an Asthma Inhaler

February 26, 2020

child asthma prime inhaler Denver Health

The most common way to take asthma medicine is with an inhaler.

The medicine from an inhaler is sprayed out and breathed deep into the lungs. Inhalers are made of medicine and propellant (the thing that carries the medicine out). When an inhaler is new, has not been used for seven days, or has been dropped, steps need to be taken to make sure the medicine is mixed in with the propellant.

This is called “priming” an inhaler. When an inhaler is not primed, the person taking it does not receive a full dose of medicine.  

The following is a step-by-step guide of what to do if you forgot to prime your inhaler.

How to prime an inhaler:

  • Step 1: Remove the inhaler from the box or packaging.
    In this instructional video, Denver Health's Kids Asthma team will show you how to prime an asthma inhaler.
  • Step 2: Remove the protective dust cap that covers the mouthpiece.
  • Step 3: Shake the inhaler hard, at least five times. Make sure the inhaler stays straight up and down while you shake it.
  • Step 4: Spray the inhaler into the air, away from your face.
  • Step 5: Shake the inhaler again before each priming spray for a total of four sprays.


When priming an inhaler that has not been used for seven days or more or has been dropped, repeat the same steps but only prime two sprays.

Remember, if you have questions, call your doctor or asthma care team.  Bring your inhaler and spacer to every visit for asthma so you can show us the technique you use.

For more information on using asthma inhalers or to make an appointment with Denver Health's kids asthma team.

En este video instructivo: cómo preparar un inhalador antes de usarlo.

The content in this article and accompanying video is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you read on

If you think you may have a medical emergency, call your doctor, go to the emergency department, or call 911 immediately.