Bisphosphonates and Atypical Thigh Bone Fracture Risk
Author: U.S. Food and Drug Administration
Published: 2010/10/14 - Updated: 2026/02/16
Publication Type: Announcement
Category Topic: Recalls, Warnings, Advisories - Related Publications
Contents: Synopsis - Introduction - Main - Insights, Updates
Synopsis: This report covers the FDA's safety warning regarding a possible link between long-term bisphosphonate use and atypical femur (thigh bone) fractures. Authored by the U.S. Food and Drug Administration, the information draws on the agency's review of available clinical data as well as findings from the American Society for Bone Mineral Research Task Force. The warning is particularly relevant for older adults and individuals with osteoporosis - a population that includes many seniors and people with disabilities - who may be prescribed bisphosphonates such as Fosamax, Actonel, Boniva, or Reclast for extended periods. The FDA's directive resulted in revised product labeling and new Medication Guides, making this a valuable resource for patients and healthcare providers weighing the benefits and risks of continued bisphosphonate therapy beyond five years - Disabled World (DW).
- Definition: Bisphosphonates
Bisphosphonates are a class of medications prescribed to prevent and treat osteoporosis by inhibiting the breakdown of bone tissue, thereby maintaining or increasing bone density and reducing the likelihood of fractures in people with weakened bones. Common brand names include Fosamax, Actonel, Boniva, and Reclast, and they are available in both oral and injectable forms. While bisphosphonates have proven effective at lowering the rate of typical osteoporotic fractures - particularly in the hip, spine, and wrist - the FDA identified a potential association between prolonged bisphosphonate use, generally beyond five years, and atypical subtrochanteric femur fractures. These atypical fractures differ from ordinary osteoporotic breaks in that they occur in the shaft of the thigh bone, often with minimal or no trauma, and may be preceded by a period of dull thigh or groin pain. The optimal duration of bisphosphonate therapy remains an open clinical question, and healthcare providers are advised to periodically reassess whether continued treatment is warranted for each individual patient.
Introduction
Possible Increased Risk of Thigh Bone Fracture With Bisphosphonates
The U.S. Food and Drug Administration has warned patients and health care providers about the possible risk of atypical thigh bone (femoral) fracture in patients who take bisphosphonates, a class of drugs used to prevent and treat osteoporosis. A labeling change and Medication Guide will reflect this risk.
Bisphosphonates inhibit the loss of bone mass in people with osteoporosis. Bisphosphonates have been shown to reduce the rate of osteoporotic fractures - fractures that can result in pain, hospitalization, and surgery-- in people with osteoporosis. While it is not clear whether bisphosphonates are the cause, atypical femur fractures, a rare but serious type of thigh bone fracture, have been predominantly reported in patients taking bisphosphonates. The optimal duration of bisphosphonate use for osteoporosis is unknown, and the FDA is highlighting this uncertainty because these fractures may be related to use of bisphosphonates for longer than five years.
The labeling changes and Medication Guide will affect only those bisphosphonates approved for osteoporosis, including oral bisphosphonates such as Fosamax, Fosamax Plus D, Actonel, Actonel with Calcium, Boniva, Atelvia, and their generic products, as well as injectable bisphosphonates such as Reclast and Boniva.
Main Content
Labeling changes and the Medication Guide will not apply to bisphosphonates used for Paget's disease or cancer/hypercalcemia such as Didronel, Zometa, Skelid, and their generic products.
"The FDA is continuing to evaluate data about the safety and effectiveness of bisphosphonates when used long-term for osteoporosis treatment," said RADM Sandra Kweder, M.D., deputy director, Office of New Drugs in the FDA's Center for Drug Evaluation and Research. "In the interim, it's important for patients and health care professionals to have all the safety information available when determining the best course of treatment for osteoporosis."
The warning follows a March 10, 2010, Drug Safety Communication announcing the FDA's ongoing safety review of bisphosphonate use and the occurrence of atypical femur fractures. The FDA has since reviewed all available data on bisphosphonate use, including data summarized in the American Society for Bone Mineral Research Task Force report. The report recommended additional product labeling, better identification and tracking of patients experiencing these breaks, and more research to determine whether and how these drugs cause the serious but uncommon fractures.
Based on the FDA's review, the Warnings and Precautions section of all bisphosphonate products for osteoporosis will be revised, and the FDA will require the inclusion of a Medication Guide to better inform patients of the possible increased fracture risk.
The FDA recommends that health care professionals be aware of the possible risk in patients taking bisphosphonates and consider periodic reevaluation of the need for continued bisphosphonate therapy for patients who have been on bisphosphonates for longer than five years.
Patients taking bisphosphonates for osteoporosis should not stop using their medication unless told to do so by their health care professional. Those taking bisphosphonates also should report any new thigh or groin pain to their health care provider and be evaluated for a possible femur fracture.
Patients and health care professionals should report side effects with the use of bisphosphonates to the FDA's MedWatch Adverse Event Reporting program.
Insights, Analysis, and Developments
Editorial Note: The FDA's warning on bisphosphonates and atypical femur fractures highlighted a difficult tradeoff at the heart of osteoporosis treatment: the same drugs that reduce the risk of common osteoporotic fractures may, over prolonged use, contribute to a rare but serious type of thigh bone break. For the millions of older adults and people with disabilities who depend on these medications to maintain bone density and avoid debilitating hip and spine fractures, the advisory did not suggest abandoning bisphosphonates altogether - rather, it called for more careful, individualized evaluation of how long patients should remain on them. The inclusion of updated labeling and Medication Guides was a meaningful step toward giving both patients and clinicians the information they need to make better-informed decisions, and it underscored the importance of ongoing dialogue between patients and their healthcare providers about the duration and necessity of any long-term drug regimen - Disabled World (DW).Attribution/Source(s): This quality-reviewed publication was selected for publishing by the editors of Disabled World (DW) due to its relevance to the disability community. Originally authored by U.S. Food and Drug Administration and published on 2010/10/14, this content may have been edited for style, clarity, or brevity.