Is Your Asthma Inhaler Running on Empty?


Did you know that you might be using your asthma inhaler long after the medicine is gone? Sometimes it’s hard to tell when an inhaler is empty. If you have a newer dry powder inhaler, like Flovent Diskus (fluticasone propionate), it may come with a built-in dose counter to let you know when it’s empty. Some of the newer inhalers show a particular color when the canister is empty. But the older type inhalers, like Ventolin and Proventil (both albuterol), have no built-in mechanism to help you know when the canister is empty.

You may be simply guessing the number of doses left until your inhaler “feels” empty. Or you may believe that the canister contains medicine if you hear liquid when shaking it. Some people try to “see” or “taste” a test dose sent into the air. But the medicine often runs out before other substances that are used to make the medicine come out of the container. So what you hear, see, or taste might only be these substances, not the medicine. Breathing these substances without the medicine could cause your symptoms to worsen. Some people also believe that an empty inhaler will float, but this is not a reliable test. You can get different results depending on whether the stem of the inhaler is up or down in the water. Also, some inhalers will float when they are full.

Don’t get caught with an empty inhaler. Even the newer inhalers require you to pay attention to the built-in dose counter. One elderly man was just hospitalized with breathing problems when he failed to notice that the dosage counter on his Serevent Diskus (salmeterol) read “zero.” The counter showed the last five doses in red, but the numbers were very small and hard to see. And the inhaler continued to make a clicking sound, as if it was loading the medicine, even after it was empty.

To make sure your inhaler always contains medicine: Know the number of doses. Read the label on your medicine, or the paper inside the box, to find out the number of doses in your inhaler. Track the puffs. On newer inhalers, learn how to read the color system or dose counter. If you use an older inhaler, keep track of the number of puffs you use. You can buy stickers ( to put on the inhaler and check off each puff. Or you can buy a reusable electronic “doser” ( to help record each puff (but not with ipratropium, cromolyn, or nedocromil, because the doser may block the sprayer).

Know when to get refills. If you regularly use an older inhaler, figure out how many days it will last. For example, if you use 2 puffs, 3 times a day, that equals 6 puffs each day. Most inhalers will give you 200 puffs of medicine. If you divide 200 puffs by 6 puffs each day, that means that your inhaler will last 33 days, or 1 month. Mark your calendar a week before to remind you to refill your prescription. For inhalers used only when you have symptoms, refill your prescription when 20-30 doses remain. Throw out when empty. Always throw away the inhaler when you reach the number of doses listed on the label. Keep a diary. As recommended by the National Heart, Lung, and Blood Institute, keep a diary of your asthma symptoms and all of the medicines you use to control your asthma. Bring the diary with you when you visit your doctor.

Created on July 1, 2004

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