Second case-control study finds no elevated risk
Sørensen and associates conducted a case-control study using medical databases in Denmark and concluded that there is no increased risk of atrial fibrillation and flutter with use of an oral bisphosphonate. They identified 13,586 patients who had atrial fibrillation and flutter and 65,054 patients who did not. Of these, 435 cases (3.2%) and 1,958 controls (2.9%) were current users of a bisphosphonate for osteoporosis. Etidronate and alendronate were used with almost the same frequency among cases and controls. The adjusted relative risk of atrial fibrillation with current use of a bisphosphonate, compared with nonuse, was 0.95 (95% CI, 0.84–1.07). New users had a relative risk of 0.75 (95% CI, 0.49–1.16), broadly similar to the estimate for continuing users (relative risk, 0.96; 95% CI, 0.85–1.09).
Bottom line? There is no compelling evidence that oral bisphosphonates cause an increase in atrial fibrillation. Even in the smaller case-control study that found a suggestion of elevated risk, the authors think that, at most, 3% of cases of atrial fibrillation might be attributable to oral alendronate.
An approach to osteonecrosis of the jaw among bisphosphonate users
Khan AA, Sándor GK, Dore E, et al. Canadian consensus practice guidelines for bisphosphonate-associated osteonecrosis of the jaw. J Rheumatol. 2008;35:1391–1397.
Since 2003, when the first reports of osteonecrosis of the jaw (ONJ) in patients receiving bisphosphonates were published, there has been widespread uncertainty among patients, physicians, and oral surgeons about diagnosis, identification of individuals at risk, prevention, and management of this troubling disorder (FIGURE 1).
To address these concerns, a multidisciplinary task force was convened by the Canadian Association of Oral and Maxillofacial Surgeons to systematically review the data. The task force included representatives from national and international societies representing the disciplines of oral surgery, dentistry, oral pathology, oral medicine, endocrinology, rheumatology, and oncology.
After reviewing the data, the task force made the following recommendations:
- In all oncology patients, a thorough dental examination, including radiographs, should be completed before IV bisphosphonate therapy is initiated. In this population, any invasive dental procedure is ideally completed before the start of high-dose bisphosphonate therapy. For nonurgent procedures in current users of bisphosphonate therapy, the drug should be discontinued 3 to 6 months before the dental treatment.
- Nononcology patients who are starting oral or IV bisphosphonate therapy do not require a dental examination beforehand, provided dental care is appropriate and oral hygiene is good.
- All patients taking a bisphosponate should be encouraged to stop smoking, limit alcohol use, and maintain good oral hygiene.
- Patients who have already been diagnosed with ONJ are best managed with supportive care, including pain control, treatment of secondary infection, and removal of necrotic debris. Aggressive debridement is contraindicated.
These recommendations are extremely helpful, especially because they make it clear that the average patient who has osteoporosis does not need to discontinue therapy before undergoing a dental procedure. Nor do patients who are about to embark on therapy—oral or IV—need any special dental examination as long as they maintain good oral hygiene and dental self-care.
Task force members were identified on the basis of their knowledge and expertise in the diagnosis and management of ONJ.
FIGURE 1 Osteonecrosis of the jaw
Blood flow to bone tissue is decreased in osteonecrosis of the jaw, leading to death of that tissue and the eventual collapse of bone.
ILLUSTRATIONS BY ROB FLEWELL FOR OBG MANAGEMENT
Distinctive fracture pattern linked to long-term alendronate
Neviaser AS, Lane JM, Lenart BA, Edobor-Osula F, Lorich DG. Low-energy femoral shaft fractures associated with alendronate use. J Orthop Trauma. 2008;22:346–350.
Patients who sustain a fracture of the proximal femoral shaft after minimal or no trauma are likely to be long-term users of alendronate, according to a recent study. These fractures are characterized by a simple transverse pattern, “beaking” of the cortex on one side, and hypertrophy of the diaphyseal cortex (FIGURE 2).
In a retrospective study, Neviaser and colleagues blindly reviewed both radiographs and medical records of 59 patients who had femoral-shaft fractures. Among the 25 users of alendronate, 19 had experienced low- or no-trauma fractures with this distinctive pattern; only one nonuser had (odds ratio, 139.33; 95% CI, 19.0–939.4; p<.0001). This fracture pattern was 98% specific to alendronate use.
The average duration of alendronate use in patients who had this fracture pattern was significantly longer than in those who did not (6.9 years vs 2.5 years, respectively; p=.002). Only one patient with this fracture pattern had been taking alendronate for less than 4 years.
FIGURE 2 Low-impact femoral fracture
Simple transverse fractures of the proximal femur after low or no trauma have been linked to long-term alendronate use.