Around the world, millions of older women and a smaller number of older men have been taking a drug to prevent hip fractures and fight osteoporosis, a disease caused by low bone mass and bone deterioration. Now some doctors are concerned that patients who have taken the drug, Fosamax, and similar medications for four to five years may be at risk for sudden fractures of the femur, the main thigh bone. VOA's Melinda Smith has details about possible side effects of the drugs, and what the U.S. government's health agency is doing about it.