I started the Fosamax when I started prednisone. I had concerns about side effects but was more concerned about losing bone ( I have osteopenia). When my doctor added methotrexate after two years on the prednisone I told him that was too many drugs that affect my GI tract and I wanted off the Fosamax. He said that was fine because I had gotten to a lower prednisone dose and bone loss was not as much of a problem. My bone density increased about 10% while on the Fosamax so I am glad I took it. I had no apparent side effects. I will request a DEXA scan at my next visit and if I have lost significant bone I will go back on the Fosamax until I get off prednisone.