I alternate between Oxycodone HCL 5mg PO, TID and Diclofenac Sodium 25mg PO, BID for chronic spinal, bursitis and arthritis issues. Sometimes if I just switch without tapering off of Diclofenac first and the 2nd day of taking Oxycodone then I vomit. Yesterday was the worse because, I vomited 3 X, felt weak, seeing stars, chills, sweats and fatigue. My throat bled because, I vomited so hard and I taste like a waxy taste in my burps. I took a pantoprazole today and feel better. Why does this happen?