Risedronate sodium (Actonel) and risedronate sodium with calcium carbonate (Actonel Combi) listing for osteoporosis in patients at high risk of fracture

The Pharmaceutical Benefits Scheme (PBS) restriction for the bisphosphonate, risedronate, was extended on 1 August 2007 to allow the treatment of osteoporosis among patients aged 70 years or older with a bone mineral density (BMD) T-score of –3.0 or less, but without an existing minimal trauma fracture. Use of this medication was previously restricted to patients with established osteoporosis and a fracture due to minimal trauma. The initial authority application must state the date, site (femoral neck or lumbar spine) and score of the qualifying BMD measurement.

The change in listing brings risedronate into line with alendronate (Fosamax), which is the only other PBS-listed medicine for use in people without an existing fracture [refer to the April 2007 NPS RADAR review 'Alendronate (Alendro Once Weekly, Fosamax Once Weekly, Fosamax Plus) for osteoporosis in people at high risk of fracture'. The decision was based on a cost-minimisation analysis of risedronate compared with alendronate. The Pharmaceutical Benefits Advisory Committee (PBAC) agreed that risedronate (35 mg weekly) and alendronate (70 mg weekly) were similarly effective for a similar cost. Risedronate has been shown to reduce the absolute risk of vertebral and non-vertebral fractures.1,2 However, to further minimise the risk of fracture, prescribers should continue to provide patients with advice on lifestyle measures (weight bearing and balance exercises, dietary changes and exposure to sunlight) and provide interventions such as calcium and vitamin D supplementation, hip protectors and falls prevention programs.3