It is definately true that some nose sprays resrict blood vessels, when we have a cold or allergies our blood vessels swell up and that causes our noses to feel plugged up. Nose sprays have a small amount of an amphetamine. This chemical reduces the size of the blood vessels.
I personaly would stay away from nose sprays and coke period.
Then go talk to your doctor.
And then leave it at that.
....Joe