mine is the blue bricanyl inhaler <the most common ones> though most doctors have started using ventolin <grey coloured spray ones> they can be used as often as you need them but you may get the shakes from them.
they wouldnt keep you awake though. but your symptoms could. i often wake a lot during the night when im ill.
You can overdose - BUT the dose you need to take would be quite high. If you need it, you can probably take up to 10 puffs in a go (but I didn't say that). If you had to go to hospital because you weren't using it enough and couldn't breath, they would almost def tell you to take 10 - bu they are supervising you. if your heart starts racing, or you feel light headed, then sit down. Keep a count of what you are taking, let the GP know if its going up in teh next few days - in theory, if you are on anti biotics, your need for the inhaler should go down not up as the anti b's kick in.
Please check you are using the correct technique. If you are then in the short term you should use it as often as required but if after 3 days use on antibiotics and using inhaler you notice no improvement in symptoms go back to your dr
My aunt used to go through a blue puffer every day or two for very many years. It will give you the shakes and possibly palpitations, but if you have needed it to get that far then it's the least of your worries. Tink has four twice a day and when she's having trouble she has ten in a go. I was given atropine at one point for her but it was changed back because they said she needed to be able to have as many as it took to bring her out of an attack.
As others have said - won't cause you major problems if you have too much but can make you shaky and your heart beat faster. If you think you are using it alot then go back to your GP and let them know, it may be you need something else. Also it may help you to take your inhaler more effectively if you take a spacer device, this is like a little container you spray the medicine through and means you don't have to coordinate the inhaler spray and your breathing quite so much which can be difficult if you are breathless.
I am asthmatic and I was told once when in hospital with bronchitis that it is advisable not to take too much because then if you do have a bad attack the nebuliser they put you on in hospital won't be effective