GENERAL
DENTISTRY
CHEMOTHERAPY
MEDICATION
The
Food and Drug Administration and Novartis Pharmaceuticals Corporation
have each issued a drug precaution for health professionals
regarding a condition known as Osteonecrosis of the Jaw (ONJ).
According to these precautions, this condition has been observed
in cancer patients who undergo invasive dental procedures such
as dental implants or tooth extractions while receiving treatment
with intravenous bisphosphonates. ONJ can cause severe, irreversible
and often debilitating damage to the jaw.
The two intravenous
bisphosphonates that were mentioned in the precautions are marketed
by Novartis under the trade names Aredia and Zometa. The precautions
are available on the FDA Web site as a general background docket
and a Medwatch letter to dental health professionals .
Bisphosphonates, also known as bone-sparing
drugs, are commonly used in the treatment of osteoporosis and
cancer that has spread to the bone Doctors prescribe intravenous
bisphosphonate therapy, which was the subject of the precautions,
for patients with cancer that has spread to the bone to help
decrease associated pain and fractures. In addition, emerging
research is exploring the ability of intravenous bisphosphonate
therapy to inhibit the spread of some cancers to the bone.
Doctors also
prescribe an oral dose of bisphosphonates for patients at risk
for osteoporosis to help delay the onset of disease by slowing
the natural progression of bone tissue destruction, or to reduce
its complications. Orally administered bisphosphonates were
not the subject of the drug precautions. However, the FDA noted
that there have been anecdotal reports of ONJ in association
with oral bisphosphonates administered for osteoporosis.
Osteonecrosis
literally means death, or necrosis of bone. According to the
National Osteonecrosis Foundation, the many risk factors for
osteonecrosis can be divided into two cateogries: definite and
probable. Definite risk factors include major trauma, fractures,
dislocations, Caisson Disease, Sickle Cell Disease, post-irradiation,
chemotherapy, Arterial Disease and Gaucher’s Disease.
Probable risk
factors include corticosteroids, blood clotting, alcohol, lipid
disturbances, connective tissue disease, pancreatitis, kidney
disease, liver disease, lupus, and smoking.1
The FDA recognizes
additional risk factors associated with the development of osteonecrosis
(not limited to the jaw) in cancer patients, such as female
sex, advanced age, edentulous regions, combination cancer therapy,
blood dyscrasias/metastatic disease, anemia coagulopathy, surgical
dental procedures, and prior infection. 2
Of course, the
decision about what treatment to provide to a patient must be
made by a periodontist in the exercise of his or her best judgment.
However, in light of the precautions, periodontists are advised
to determine whether a patient is receiving intravenous bisphosphonate
therapy. If so, invasive dental procedures should be avoided
unless absolutely necessary. Conversely, if a periodontist becomes
aware that a patient is going to be treated with intravenous
bisphosphonates, any needed invasive dentistry should, if possible,
be performed before the initiation of such treatment. Finally,
periodontists should endeavor to identify ONJ and other oral
complications of cancer and cancer therapy.
