Two advisory panels of the Food and Drug Administration will consider on Friday whether to recommend requiring women who use popular bone drugs like Fosamax to take “drug holidays” because of rising concerns about rare side effects with long-term use, according to people involved in the review. The panels and F.D.A. staff members are also expected to conduct a comprehensive safety review of the medical evidence to date, after 16 years of growing use of the drugs, to determine whether they have proved to be safe and effective in use longer than three to five years. The recommendation could affect many of the estimated four million women in the United States who take the drugs, called biphosphonates. Biphosphonates inhibit a bone renewal process called resorption, adding bone mass, but possibly causing brittleness as well.
