Early detection and guidance for patients undergoing bisphosphonate therapy
Bisphosphonates are drugs that influence bone metabolism and slow the rate of bone resorption. They are used for treating osteoporosis and other benign bone conditions, as well as in patients with bone metastases of malignant tumours.
Patients suffering from osteoporosis usually receive bisphosphonates as oral medication (weekly tablets) or in some cases as infusions (three-monthly or annually). Bisphosphonates thus reduce the frequency of bone fractures.
In patients with cancer and bone metastases, bisphosphonates (intravenous, four-weekly, at higher concentration) are used to reduce pain, retard the rate of progression of the metastases and lower the frequency of bone fractures.
Bisphosphonates are efficient and highly efficacious drugs which improve sufferers’ quality of life in this regard.
In 2003, however, an adverse side effect of bisphosphonates came to light which can have the opposite effect: bisphosphonate-related osteonecrosis of the jaw (BRONJ). This condition is characterized by exposed bone in the oral cavity without healing tendency. Following tooth extractions or injuries such as denture sores, wound-healing disorders may occur that can persist for weeks. Additionally, other symptoms may appear such as pain, inflammation, abscesses, nerve malfunction, fistulas, oroantral communication (a connection between the oral cavity and maxillary sinus) and even jaw fractures.
The condition of bisphosphonate-related osteonecrosis reduces the quality of life of the affected patients. To date, it has not proved possible to precisely determine the incidence of bisphosphonate-related osteonecrosis of the jaw (BRONJ). It is certain, however, that this condition is triggered very much less often by an oral administration (tablets e.g. Fosamax and Actonel) than by intravenous bisphosphonates (e.g. Zometa, Aredia, Bonviva and Bondronat).
Current studies indicate a prevalence of around 0.1% for the tablet form and up to 20% for intravenous administration.
The precise causal mechanism that leads to BRONJ is not yet known. However, the latest research findings suggest that inflammation in the mouth and jaw region has a significant impact on the manifestation of the condition. Owing to an acidic pH value (such as occurs with an inflammation), bisphosphonates are released from bone and accumulate locally. The jaw region is particularly prone to inflammation because of the presence of teeth.
Indeed, according to the latest (4th) German study on oral health, some 92% of people over 65 years have moderate to severe inflammation of the periodontium (known as periodontitis).
“All things are poison, and nothing is without poison; only the dose permits something not
to be poisonous”, as was recognized by Paracelsus as long ago as the 16th century. And this certainly applies to bisphosphonates. In the event of an excessive local concentration, as caused by the above mechanism, bisphosphonates can have a harmful effect on the surrounding tissue and, in the worst case, lead to BRONJ.
To avert this, we recommend that you take preventive measures.
We will be happy to advise patients facing or undergoing bisphosphonate therapy concerning their personal risk profile (risk of contracting a bisphosphonate-related necrosis of the jaw). And we will be glad to offer guidance in discussing the possible risks of an upcoming implantation in relation to bisphosphonate therapy.
We will also be happy to discuss with you the optimal timing of surgical intervention (including dental implants) with regard to ongoing bisphosphonate therapy. We do not give general recommendations on continuation of bisphosphonate therapy, possible adjustment of existing medication or the necessity of bisphosphonate therapy.
We will, however, be happy to refer you to experts on these issues.
We cooperate closely with the Osteologisches Schwerpunktzentrum in Munich, an osteological centre for which we act in an advisory capacity.
If, despite preventive measures, BRONJ develops, we recommend surgical therapy. To find out more about this therapy, visit www.medizinundaesthetik.de/en/necrosis-of-the-jaw/