I don't think it is the chewing part, due to the fact that you have five of them in you! Vicoprofen (And VICO-friends) are not time release like Oxys, so it wouldn't matter if you chewed or swallowed them whole (If that is what you meant by the chewing part.
Now if you took five of these Vicoprofens and aren't use to taking Hydrocodone or any other opiate, you are in for one helluva buzz. Now the profen part means it has Ibuprofen in it, not sure as to how many mg of in each! Just don't make it a habbit on eating so many at one sitting.