Guide to Asthma
Appendix 3: Using Your Inhalers Effectively
At present most inhaled asthma medications come in the form of a metal canister inside a plastic dispenser. Inside the canister is medication in aerosol form. To deliver the medication, one presses down (and then releases) the canister in its holder; from its nozzle is delivered a spray containing each time the same amount of medication. This type of inhaler is called a "metered-dose inhaler" or MDI. Before pressing the canister to release the medication, it is good to give it one or two shakes so that the medication is evenly mixed within the canister, and, of course, be sure to remove the cap that covers the mouthpiece.
The key to proper use of these inhalers is drawing the spray or mist released from the mouthpiece of the inhaler deep into the lungs and onto the bronchial tubes. We recommend that you put your lips and teeth tightly around the mouthpiece of the inhaler. Alternatively, it is also proper to hold the mouthpiece a distance of about one inch from your opened mouth.
Then, three steps are important. First, start breathing in as soon as the spray has been made. If you wait to breathe in too long after making the spray, you lose a lot of medication that settles onto your tongue and mouth rather than being drawn onto your breathing tubes. At the other extreme, if you breathe in deeply before the spray is made, you will not have enough breath left to pull the medicine onto the bronchial tubes. So, to do it just right, at the same time that you are pressing down on the canister and making the spray, begin to breathe in.
Second, breathe in slowly. It takes time to distribute the medication to the thousands of bronchial tubes; too fast a breath puts most of the medicine onto the back of the throat and the upper breathing passageways only. Try not to rush as you breathe in; it should take about 3-4 seconds to pull in a slow, full breath.
Third, hold your breath for a few seconds at the end of the slow, deep breath. If you breathe out immediately, you lose some of the medication in what you exhale. Give the medicine a chance to settle onto the breathing tubes by holding your breath for about 5 seconds before exhaling.
A different medication delivery form is the dry powder inhaler. With this device, a fine micronized powder is released as you pull in a breath through the inhaler. No pressurized spray is generated. It is the force of the inhaled breath that puts the powder into its aerosolized form.
Spacers can assist in the delivery of inhaled medications. Spacers are holding chambers into which the medicine is sprayed and from which one then breathes in the medicine. Spacers serve two major purposes: they help to improve coordination of inhaled medications, and they reduce the amount of inhaled medication that is deposited onto the tongue and back of the throat. They can be used with the pressurized metered-dose inhalers but not with dry powder inhalers.