PPA, yes, it it phenylpropanolamine.

I do know & have known people in the past (a lot of them too) that have used this drug. Although I presonally have never had to use it on any of my pets. And I also remember some brief history on the drug from when I worked at a vets office. The only side affects that I know of are restless, (but not really nervousness like you described) and high blood pressure. Both are fairly rare but the first is more common.

I am sorry that I can not be of more help. I would reccomend a trip to your vet to see what they say. It may be something else that is causing these symptoms or it could be the drug. If it is the drug there are others available for you to try. Good luck.