Yes, they have changed the propellant in inhalers. The old ones are no longer available. Same reason Rhinocort is only available in a spray now.
At any rate, you may need to up your dosage on your preventive inhaler....
Flovent,Advair,whatever for a while. Check with your doctor. Also, the new ones are not made to used with a spacer. If you are using your preventive inhaler (new type) with a spacer, you may not be getting enough of themed.
Once again, check with your doctor. I did.