Intravenous pamidronate in the treatment and prevention of osteoporosis

Background: Potent oral bisphosphonates are the mainstay of therapy for osteoporosis. However, there are patients who cannot have oral bisphosphonates (e.g. because of gastrointestinal side-effects). Therefore, we wanted to examine the effects of intermittent i.v. pamidronate (APD) on bone mineral density (BMD) in patients who needed bisphosphonate therapy but could not have oral bisphosphonates. Aim: To assess BMD before and after intermittent i.v. APD in patients requiring a bisphosphonate either for the prevention of osteoporosis on concurrent steroid therapy or for the treatment of osteoporosis. Methods: This was a retrospective audit of 84 consecutive patients at risk of fractures commencing APD between October 1997 and May 2000. Patients were treated with intermittent i.v. APD. BMD as measured by dual-energy X-ray absorptiometry before and after APD was the main outcome. Results: The mean length of treatment and mean total APD dose were 16.8 +/- 7.0 months and 186.1 +/- 79.5 mg respectively. The reasons for using APD were failure to qualify for oral bisphosphonates on the pharmaceutical benefits scheme due to lack of documented minimal trauma fractures (58%), symptomatic gastro--oesophageal disease (20%), intolerance of oral bisphosphonates (18%) and lack of efficacy of calcitriol (4%). Mean baseline T-score at lumbar (L) 2-4 spine and femoral neck were -1.54 +/- 1.22 and - 2.87 +/- 1.19, respectively. From baseline to after APD treatment, there was a significant increase in L2-4 BMD (0.883 +/- 0.175 vs 0.912 +/- 0.176 g/cm(2), P < 0.001, mean increase +3.5%), in femoral neck BMD (0.667 +/- 0.137 vs 0.680 +/- 0.134 g/cm(2), P = 0.001, mean increase +2.1%) and in trochanteric BMD (0.549 +/- 0.129 vs 0.566 +/- 0.132 g/cm(2), P < 0.001, mean increase +3.1%). One-third of the patients were on oral glucocorticoids at the time of the present study and they had a similar increase in BMD compared to patients not on gluco-corticoids. Mild side-effects occurred in seven patients, none of whom discontinued treatment. Conclusion: Intermittent APD increases BMD and may be a suitable alternative for patients who cannot have oral bisphosphonates.