Getting the Most from Your Inhaled Medications
Many of the medications that we use to treat asthma are given in the form of mists that must be inhaled to have an effect. In this way, more medication gets to where the problem is in asthma—the air passageways (bronchial tubes) of the lungs—and fewer unpleasant medication side effects are likely to occur compared to medications that are swallowed. However, getting the medication from a canister held in one's hand to the surface of thousands of bronchial tubes in the lungs is not always easy. It requires a coordinated hand and breathing action that can be tricky to master. In this pamphlet we review how to get the most medication—and the most benefit—from the inhaled route of delivery.
Breathing in the Medication Properly
Most of the inhaled medications at present come in the form of a metal canister inside a plastic dispenser. (Some bronchodilators are held in liquid form inside a plastic canister). 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 important 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.
A Three-step Approach
First, press the inhaler and then start breathing in as soon as the spray has been made. If you wait too long to breathe in after pressing the inhaler, 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 fully 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, 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.
There is no need to wait one minute between puffs. As soon as you have completed the careful inhalation of one puff, you are ready to proceed with the next.
Using Inhalational Aids or "Spacers"
Your doctor may recommend that you use a simple device, called a "spacer," with your metered-dose inhaler. Spacers have two advantages: they often improve coordination between delivery of the medication from the inhaler and breathing it onto the bronchial tubes; and they reduce the amount of medication that settles in your mouth and throat.
Spacers come in a variety of forms, but the basic concept is to provide a small chamber into which the spray from your inhaler is delivered, and then you breathe in the medication from the chamber. For some spacers (for example, the InspirEase® and Optihaler® models), you need to take the metal canister from its plastic holder to insert it into the spacer device. For others (e.g., Aerochamber®, Optichamber®, and Vortex®), the canister and plastic holder together fit into one end of the spacer chamber. After the medication has been sprayed into the spacer chamber, it remains suspended within the chamber for a few seconds. Now, with your lips and teeth sealed around the mouthpiece of the spacer, having sprayed the medication into the chamber, you can slowly breathe in the air (and medication) from the chamber. Many spacers have a built-in whistle that sounds when you breathe in too fast. One of the corticosteroid inhalers (Azmacort®) has a small spacer built into each MDI device that you buy.
Although it is tempting to fill your spacer with all of your medication doses and then take one big breath in, this method does not work. Use one breath in for each puff of your medication.
Knowing When Your Inhaler is Empty
It is sometimes difficult to be sure when your metered-dose inhaler has become empty. Depending on the medication, different inhalers contain different numbers of sprays. The number of sprays contained within a full canister is written on the box in which the medication is sold and in the package insert; each canister reliably contains at least as many sprays as indicated. If you use exactly the same number of sprays of medication each day from one inhaler, you can keep track of when the inhaler will become empty by calculating the number of sprays per day times the number of days of use.
Alternatively, you can make an estimate of how full or empty your metal canister is by removing it from its plastic holder and floating it in water. A full canister floats with its nozzle facing down or sinks to the bottom of the container of water. An empty canister bobs on the surface of the water, almost horizontal in position. This technique is not very precise and cannot readily distinguish a nearly empty canister from a totally empty one.
Alternative Types of Inhalers
Two alternative types of inhalers are currently available; each one is specific for the medication that it delivers and cannot be used with other inhaled medications. The bronchodilator pirbuterol (brand name: Maxair®) comes in the form of an Autohaler®. The medication is released from the pressurized canister not by pressing down on the canister but by the force of breathing in with one's lips tightly sealed around the mouthpiece. The Autohaler® is triggered by the flow of air, thereby ensuring that you are breathing in at the same time that the medicine is delivered.
Dry-powder inhalers do not involve any pressurized spray. The medication, in the form of a very fine powder is pulled into the lungs by the force of one's breath. Examples of dry-powder inhalers include the Turbuhaler® (used to deliver the steroid medication, budesonide); the Diskus® (used to deliver the long-acting bronchodilator, salmeterol—Brand name: Serevent®); and the combination inhaled steroid and long-acting bronchodilator (Brand name: Advair®).