It is a sort of catch 22 -
pancreatitis is painful, so you take painkillers, which exacerbate the
pancreatitis and cause more
pain, and lead to you using more painkillers, ect...I feel in your specific case, I would taper faster. Trust me, you do not want to cause any additional damage to your pancreas, it is VITAL to so many processes in your body, and these problems will catch hup with you eventually.
Here is my suggestion for you:
Vicodin has a half life of about 4 hours.