When i use my mdi, how long should i press on the canister? if i continue to press on the canister throughout my inhalation is that wasting propellant

MDI Use...: When you press on the canister of the inhaler, only a certain amount comes out no matter how long you press. The best way to use an inhaler is with a spacer device. With that, you can press the canister first and then inhale the medication out of the spacer. This will allow the medication in the spacer to get to your airways and not wind up in your mouth. Hope this helps! good luck!!