Hopefully you were able to get in touch with an emergency vet. Here's a good article on OTC meds and dogs/cats.
http://www.canismajor.com/dog/nsaids.html
I had a friend who gave her dog OTC meds thinking that because it was safe for humans that it was safe for her dog...sadly, the pup ended up passing away. Dogs and cats' livers process these meds
so differently than we do.