USA. In response to spontaneous reports of osteonecrosis of the jaw in patients receiving bisphosphonates, Novartis has issued a 'Dear Doctor' letter advising of changes to the US prescribing information for the bisphosphonates pamidronic disodium (Aredia) and zoledronic acid (Zometa). The 'Precautions' sections of the US package inserts for both these products now state that there have been reports of osteonecrosis of the jaw involving patients with cancer receiving bisphosphonates, many of whom were receiving concomitant corticosteroids and antineoplastics. Most reports were associated with dental procedures, and the package inserts recommend that patients with risk factors for osteonecrosis undergo dental examination and preventive dentistry prior to starting bisphosphonate therapy, and that invasive dental procedures should be avoided during treatment. It is not known whether discontinuation of bisphosphonates reduces the risk of osteonecrosis in patients requiring dental procedures. Information regarding osteonecrosis has also been included in the ´Post-Marketing Experience' sections of the package inserts.
'Dear Doctor' letter from Novartis, 24 September 2004. Available on the Internet at www.fda.gov
Reports in WHO-file: Osteonecrosis: Pamidronic acid 54, zoledronic acid 38.