E-Poster Presentation ESA-SRB-ANZBMS 2021

Changing anti-resorptive prescription rates in the last five years (#735)

Lucy Collins 1 , Rahul D Barmanray 1 2 , Cherie Chiang 1 , Christopher Yates 1 2 , Spiros Fourlanos 1 2
  1. Department of Diabetes and Endocrinology, Royal Melbourne Hospital, Melbourne, Victoria, Australia
  2. Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Melbourne, Victoria, Australia

Background

Osteoporosis or osteopaenia affect approximately six million Australians aged > 50 years, resulting in fracture-related morbidity and mortality. The treatment dosing schedule, duration and effects after treatment cessation vary due to the different actions of the anti-resorptive medications. Importantly, a rapid increase in bone turnover markers and reduction in bone mineral density can be seen following denosumab cessation (1). Vertebral fractures have been observed eight months following the last denosumab dose due to the rebound increase of bone resorption, in contrast to bisphosphonates’ persistent skeletal action despite cessation (2). Lockdown of citizen movement in Australia occurred during the COVID-19 pandemic in 2020 causing disruption to healthcare and in-person reviews.

 

Aim

To examine national prescribing rates from 2016 to 2021 of denosumab, alendronate and risedronate.

 

Method

This retrospective audit analysed prescribing rates of anti-resorptive medications. Data was sourced from The Pharmaceutical Benefits Scheme ‘Date of Supply’. Time-based trends were analysed by two methods: a polynomial (quadratic) line of best fit (R2 = 0.8639) and an interrupted time series using a quasipoisson distribution, with comparison made between pre- and post-COVID-19 onset (March 2020) periods.

 

Results

Prescription rate of denosumab increased from 2016 to 2021. The rate has been steadily slowing with intensification of this trend noted post the onset of the COVID-19 pandemic (Figure 1). The long-term rates of prescription of alendronate and risedronate have decreased, with a notable inversion in this trend following March 2020 (Figure 2). 

 

Conclusion

The rate of denosumab prescriptions has slowed, more so following March 2020. This could be related to decreased new starts and/or decreased treatment continuation. Future research is required to determine if higher rates of rebound-associated fractures are occurring. Clinicians are urged to ensure that a strict 6 monthly dosing interval for denosumab is employed to mitigate the risk of rebound fractures.

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  1. Bone, H., Bolognese, M., Yuen, C., Kendler, D., Miller, P., Yang, Y., Grazette, L., San Martin, J. and Gallagher, J., 2011. Effects of Denosumab Treatment and Discontinuation on Bone Mineral Density and Bone Turnover Markers in Postmenopausal Women with Low Bone Mass. The Journal of Clinical Endocrinology & Metabolism, 96(4), pp.972-980.
  2. Anastasilakis, A., Polyzos, S., Makras, P., Aubry-Rozier, B., Kaouri, S. and Lamy, O., 2017. Clinical Features of 24 Patients With Rebound-Associated Vertebral Fractures After Denosumab Discontinuation: Systematic Review and Additional Cases. Journal of Bone and Mineral Research, 32(6), pp.1291-1296.