How to Know if an Inhaler Is Empty

If you rely on an inhaler to keep your asthma under control, not knowing if it is empty can be stressful. When shaken, empty and full canisters can make virtually the same sound. Sadly, there are currently no affordable devices that can provide an accurate measurement of how much medicine is left. However, there is a simple way to track your usage and determine when you will need to replace the canister. If you have not been doing this, you can also perform a simple test that will give you a rough estimate of how much medicine you have left.

Things You'll Need

• Large bowl of water

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Instructions

Track Your Usage

• 1

  Find out how many "puffs" your inhaler medicine contains per canister. You can get this information from your doctor or pharmacist and the estimates are usually quite accurate.

• 2

  Count how many puffs you take each day. If you use your inhaler the same number of times each day, divide the number of puffs in the canister by your daily number of puffs to determine how long your medicine will last.

• 3

  Create a tally sheet to record each puff if you do not use the inhaler consistently. When you reach the estimated number of puffs in the canister, it is time for a new one.

Test How Much is Left in Your Inhaler

• 4

  Remove the canister from your inhaler and place it in a large bowl of water.

• 5

  Observe how the canister lands in the water. If it floats and is almost parallel to the bottom of the bowl, it is empty. If it floats at a 45-degree angle, it is one-quarter full. If it turns upside down but the bottom remains above the water, it is half full. If it turns upside down and is completely submerged, it is three-quarters full. If the canister sinks to the bottom and lays flat against the bowl, it is totally full.

• 6

  Perform a little math to determine how many puffs are left. Multiply the estimated total of "puffs" in the canister by the fraction of medicine that is left. This will tell you how many puffs you can take before replacing the canister. For example, if the canister floats at a 45-degree angle, you should multiply the total number of puffs by one-fourth. Thus, a canister with an estimated total of 20 puffs that is one-quarter full would have five puffs left.

• 7

  Track your inhaler usage, being sure not to exceed the number of puffs that you determined were left.