It is important to know when to replace your inhaler, so that you don’t run out of medicine. The way to do this is to keep track of how many doses (puffs) are left in your inhaler.
Some inhalers have a built-in counter that keeps track of the number of puffs left. All you need to do is to replace the inhaler when the counter gets close to zero.
If your metered-dose inhaler does not have a counter, check the label or the written instructions for the number of sprays or puffs in the inhaler. It may say inhalations or actuations instead of puffs. Write down the number of puffs.
If you use your inhaler on a schedule every day:
If you only use your inhaler when you need it:
If you have a dry powder inhaler that uses capsules, you can keep track of how many doses are left by checking the number of capsules you have.
Do not put a metered-dose inhaler in water to see if it will float. Some inhalers float when they are full. Putting it in water may damage the canister. Dry powder inhalers must be kept dry or they will not work properly.
Do not shake the inhaler to see if it is empty. Even after you have used all the medicine, a metered-dose inhaler may feel as if there are puffs left. This is because there may be some gas left even though the medicine is gone. Do not shake a dry powder inhaler. It may keep it from delivering the correct dose of medicine.
Do not assume that tasting something when you use the inhaler means that there is medicine left. The medicine may have run out and you may not get your correct dose.
Do not use an inhaler past the expiration date of the medicine. The medicine may not be strong enough or it may no longer be safe to use.