MedWire News: Scientists have found no evidence to suggest that use of bisphosphonates increases the risk for atrial fibrillation (AF) and flutter.
Bisphosphonates are used to increase bone density and reduce the risk of fractures in patients with osteoporosis.
Recent clinical trial results suggested that bisphosphonates may increase the risk for AF, but data on their potential toxicity is scant and conflicting, say Henrik Toft Sørensen (Aarhus University Hospital, Denmark) and colleagues.
Sørensen and team carried out a population-based case-control study using data from medical databases in Denmark. In all, 13,586 women with AF and flutter, and 68,054 gender-matched controls were included in the analysis.
The proportion of women currently treated with the bisphosphonates etidronate and alendronate was similar in patients with AF/flutter and in controls (3.2% and 2.9%, respectively).
Patients currently taking bisphosphonates were as likely to develop AF/flutter as those not taking them, with an adjusted relative risk (RR) of 0.95. The relative risk for new current users and continuing users of bisphosphonates was 0.75 and 0.96, respectively, compared with patients who had never been treated with these drugs.
There were no significant differences in the risk for AF/flutter between patients treated with alendronate and etidronate.
The relative risk estimates were independent of number of prescriptions and the position of the AF and flutter in the discharge record, and were similar for inpatients and outpatients.
Sørensen et al conclude in the British Medical Journal: "In this large population based study we did not find that use of etidronate or alendronate for osteoporosis was associated with an increased risk of atrial fibrillation and flutter."
They note, however, that zoledronic acid was not used by outpatients and risedronate use was limited, and therefore these results "do not necessary hold for those bisphosphonates."
In an accompanying editorial, Sumit Majumdar (University of Alberta Hospital, Edmonton, Canada) commented on the implications for clinicians: "For now, beyond taking the patient's pulse and ordering an electrocardiogram when it is irregular, available evidence suggests that business should carry on as usual - the risk of atrial fibrillation associated with oral bisphosphonates seems to be vanishingly small if it exists at all, and it is unlikely to ever offset the confirmed benefits of these drugs in the prevention of fractures."
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