Managing patients on bisphosphonates
Roshan Bains explains how to treat patients who are using bisphosphonates and what to look out for.
Bisphosphonates are a group of drugs used for the prevention of bone resorption. They work by stimulating osteoblasts to produce inhibitors of osteoclast formation.
Bisphosphonates are not metabolised, but instead are slowly excreted via the kidneys and have a high affinity for bone where they can stay for up to 10 years. Dental procedures and dentures can frequently cause trauma to these areas. So, although bisphosphonates are useful in treating some diseases, their ability to impair bone healing and remodeling can lead to a condition called medication related osteonecrosis of the jaws (MRONJ).
Reasons your patient might be taking bisphosphonates
Patient’s can be administered bisphosphonates in two ways: orally and intravenously (IV). Oral bisphosphonates are less potent and poorly absorbed, they are mainly used to treat osteoporosis or osteogenesis imperfecta. IV administration is more potent and whilst used for osteoporosis, is primarily used for metastatic malignancy. The table below outlines conditions that may require treatment.
What is MRONJ?
MRONJ is defined as exposed, necrotic bone in the maxilla or mandible for more than eight weeks in patients taking bisphosphonates and have had no history of radiation therapy. It is thought to have been caused from trauma to dentoalveolar structures that have poor healing capacity due to bisphosphonate therapy.
Classifying the risk of a patient developing MRONJ
It is important for dentists to be able to identify whether their patients receiving bisphosphonate therapy are at a higher or lower risk of MRONJ. Method and frequency of administration together with length of prescription underlie risk of MRONJ. Risk of developing MRONJ is also higher in patients who’ve had a longer duration of bisphosphonate treatment.
We can classify osteoporosis patients as low risk if they are in the early years of administration and have no higher risk factors. Patients are deemed to be higher risk if they have any of the following:
- Previously diagnosed with MRONJ
- Taking high dose bisphosphonates
- Those on antiresorptive medication with other comorbidities or medications that may potentiate the effect of the antiresorptive medication
- Rare metabolic bone conditions
- Taking systemic corticosteroids or other immunosuppressants
- Undergoing coagulopathy, chemotherapy or radiotherapy
What does the guidance say?
In the past bisphosphonates were prescribed without any long-term review.
However, as the drugs and their side effects have become better understood new guidelines have been put into place by institutions such as NICE, NOGG or SDCEP. Practitioners must remember that guidance does not equate to rules. These documents have the aim of guiding decisions regarding the management of those on bisphosphonates. What may work for one patient may not work for all, and so it is up to the practitioner to use their best clinical judgment.
The adverse effects of long-term bisphosphonates therapy has raised questions about what the optimal duration of therapy should be. Both NICE and NOGG have stated that all patients should have treatment reviews after five years of treatment with alendronate, risedronate or ibandronate and after three years of treatment with zoledronic acid. NOGG guidelines are used to guide the decision about whether a patient should stop their treatment for a period of time, a score is generated and a decision is made on the outcome.
Before patients start bisphosphonate therapy, the main priority is getting them as dentally fit as feasible with emphasis on preventative care. A personalised preventative advice programme will help the patient to optimise their oral health and decrease the risk of developing MRONJ.
You should discuss the risk of developing MRONJ with the patient and give them the opportunity to raise any concerns they might have. For more complex cases (higher risk patients on bisphosphonates), seek the advice of an oral surgery/special care dentistry specialist for treatment planning.
Bisphosphonate patients should still be seen routinely for scale and polish, simple restorations and radiological review. The patient should then be allocated to either a high or low risk group of developing MRONJ and depending on the allocation, a recommended management strategy is given.
It is important to remember not to prescribe antibiotic or antiseptic prophylaxis following extractions or other bone impacting treatments specifically to reduce the risk of MRONJ. If after eight weeks an extraction socket has still not healed and you suspect your patient has MRONJ, you should refer to an oral surgery/special care dentistry specialist.