Is it ok to use an asthma inhaler after the counter reaches 0? (doctor, exercising)

[Trucker7]

Most new asthma inhalers come with counters that count to zero as you use your medicine; however, there's still a good 30-40 puffs left after you reach zero. All health sites say that you may not get the proper amount of medicine after zero and that you may only be getting the propellant used to deliver the medicine.

Now, if I shake my inhaler before each use as instructed, wouldn't that mix the medicine with the propellant evenly? If that's the case, shouldn't each puff, from the first one to the very last one, have the same amount of medicine and propellant? I don't want to risk not getting my correct dose, but I don't want to waste a perfectly good 30-40 doses either.

[sweetana3]

I can tell that there is nothing left in my inhaler because it does not give me the same relief. I forgot to check and was very sorry I did.

Would not chance it.

I got the lecture from my doctor that asthma can be a killer and I have had one emergency room visit that I never want to repeat.

[markusm]

I know this is an old post, but before I actually went to the doctor for my condition (COPD, not asthma) I was given an inhaler by a co-worker due to difficulties breathing while exercising. After the inhaler reached 0 I threw it in a drawer, but several days later was having a lot of difficulty breathing. Since it was late at night, taking a pill bronchodialator (primatine tablets) was not an option, so I grabbed the inhaler and took a couple of puffs from it. Shortly I was breathing fine, so yes, there is still some of the medicine in it after it hits 0. Not that I'm saying you shouldn't try to have a recent one on hand, but if you have nothing else, use it even if it's hit 0.

Also, as with spray paint, I would assume that if not shaken properly you'd probably run out of propellant before the intended contents.