How is medicine delivered in an asthma inhaler?
Asthma inhalers are handheld devices used to deliver asthma medicine into the airways. The inhaler delivers a puff of medicine as the person breathes in.
Common types of asthma inhalers include reliever inhalers to help with symptoms such as wheezing, and preventer inhalers to be used to help prevent symptoms.
Asthma inhalers can deliver medicine in a variety of ways, including:
- Metered dose inhalers (MDIs): An MDI delivers asthma medicine through a small, handheld aerosol canister. The MDI gently puffs the medicine into your mouth when you press down on the inhaler and you breathe the medicine in.
- Dry powder inhalers (DPIs): DPIs require you to breathe in deeply as the medicine enters your lungs. These asthma inhalers may be difficult to use, especially during an asthma attack when you cannot fully catch a deep breath. Read the instructions carefully for each DPI as they vary considerably. The technique you learn for one type of inhaler often does not apply to others.
What types of medicines are used in asthma inhalers?
Medicines used in asthma inhalers are anti-inflammatory (steroid medicines) bronchodilators (beta-2 agonist medicines) or both (a combination inhaler).
Anti-inflammatory asthma inhalers: anti-inflammatory medicines used in asthma inhalers help prevent asthma attacks and reduce swelling and mucous production in the airways. These anti-inflammatory medicines help people get better asthma control.
Bronchodilator asthma inhalers: bronchodilator asthma inhalers are either short-acting or long-acting. They are used to ease asthma symptoms such as wheezing, shortness of breath and coughing. Inhaled bronchodilators dilate or widen the airways, which helps relieve asthma symptoms much faster than oral medicines.
How can I be sure there is medicine in my asthma inhaler?
Many new inhalers include a counter. However, with others, knowing how much medicine is available in an asthma inhaler is a problem. Many people with asthma say they use their inhalers until they can no longer hear a "puff" sound when they try to spray it. The problem can be that most asthma canisters generate a puff sound long after the asthma medicine has gone. You may be using the asthma inhaler properly and hearing the puff sound when you spray it, but the asthma inhaler canister may be completely empty. This is a serious problem when you depend on the inhaled medicine to relieve asthma symptoms.
If you do not have a counter on your asthma inhaler, mark the number of doses you use on the inhaler. Then throw away the inhaler after you have used up the number of puffs in the canister. The total number of doses in the asthma inhaler will be written on the box or canister. Mark the date on your calendar when you expect to use up all of the puffs in your new asthma inhaler and get a new asthma inhaler before this date. Keep one or two extra quick-relief inhalers at home. Carefully read the instructions that come with the inhaler. Some inhalers must be shaken before each use while others must be primed if not used for several days.