Dental abscesses symptoms and conditions

My mother was prescribed this horrible drug for prevention purposes about a year ago. She has experienced severe hair loss, unexplained cough and sore throat pain, flu-like symptoms with fever, severe headaches. Doctors prescribed sinus medication and hydrocortisone shots in the scalp for hair loss and occasional shoulder pain that was explained by her doctors to be arthritis (at times severe). She was recently diagnosed with a brain tumor and treated with temodar and radiation for brain cancer. Before fosomax, she was a very healthy 63 year woman with no health issues whatsoever. She went for annual physical and was prescribed this medication. In the last few months, her doctors increased dose of Caltrate-D from 600mg a day to 2400mg/day because of cancer treatment. Immediately, she began to experience severe neck and shoulder pain on the left side. In a few weeks, it has spread to both shoulders and upper arms. She is unable to wash lower back, raise arms to comb hair, lift herself up from sitting position, brush her teeth. A few weeks ago, she experienced the sensation of an abscessed tooth. A dentist told her several teeth would need a root canal. She has pain in upper arms that feel like burning fire. She is getting weaker in the arms. Pain is spreading to the hips. I pray this doesn't go any further and will reverse after we stop this dangerous drug. Has anyone shown signs of improvement after stopping this drug? How long did it take to see improvement? What if anything can you do for the pain and sore muscles and joints?