Pamidronate increases bone mineral density in women with postmenopausal or steroid-induced osteoporosis

Introduction: We aimed to determine the efficacy and safety of a cyclic intravenous therapy with pamidronate in patients with postmenopausal or glucocorticoid-induced osteoporosis. Methods: We enrolled 86 Austrian female patients with postmenopausal (n = 69, mean age 68.13 +/-1.14) or glucocorticoid-induced (n = 17, mean age 66.89 +/- 2.03) osteoporosis defined as a T-score of <-2.5 for bone mineral density (BMD) of the lumbar spine L1-L4. Patients received a single intravenous dose of 30 mg pamidronate at 3 months intervals. The per cent change in BMD was primary, whereas the safety and the biological response were secondary endpoints. Results: Seventy-six female patients (88%) completed study. Sixty patients received pamidronate therapy for the treatment of late postmenopausal osteoporosis and 16 patients received the same treatment for glucocorticoid-induced osteoporosis. At the end of the trial, lumbar spine (L1-L4) BMD increased significantly in patients with postmenopausal osteoporosis (P = 0.000067), whereas in patients with glucocorticoid-induced osteoporosis no significant change was observed (P = 0.724). The increase in the Ward's triangle BMD did not reach significance level in postmenopausal women receiving pamidronate (P = 0.0740). However, pamidronate treatment for glucocorticoid-induced osteoporosis resulted in a significant increase in Ward's triangle BMD (P = 0.0029). The efficacy of pamidronate treatment for postmenopausal osteoporosis was also reflected in a decrease in circulating biochemical markers for bone formation, including alkaline phosphatase and osteocalcin. In addition, pamidronate was well tolerated with no incidence of severe gastrointestinal events. Conclusion: Cyclic intravenous administration of pamidronate is well-tolerated therapy in postmenopausal osteoporosis, and increases spinal BMD. Randomized controlled studies with adequate number of patients are needed to test the efficacy of the compound in the treatment of glucocorticoid-induced osteoporosis.