question: Taking Bystolic 2.5mg. OD; Having two knees replaced next month ; been taking Instaflex for almost 2 years. it has helped  a lot, but I am Bone on Bone in both knees now. Hard to walk.I have to stop Instaflex, + Anacin, 3 x's a day ( 2 weeks before surrgery) . Is there a reaction to stopping it completely? Dr. said no Blood thiners !Dr. perscribed Tylenol with Codeine to use, if Reg. Tylenol doesn't work.