Efficacy of Combined Treatment with Raloxifene and Alfacalcidol on Bone Density and Biochemical Markers of Bone Turnover in Postmenopausal Osteoporosis

Because both raloxifene (RLX) and alfacalcidol (ALF) have been established as therapeutic agents for osteoporosis, it is tempting to speculate that the combination therapy of RLX and ALF might provide benefits over that of either one alone. However, the efficacy of the combination therapy has not been reported yet. The purpose of this study was thus to assess the efficacy of the combination therapy on bone mineral density (BMD) and bone turnover in patients with postmenopausal osteoporosis. Sixty postmenopausal patients (mean age 71.62 +/- 9.9 years) with untreated osteoporosis were selected for this study, and were randomly divided into two groups by therapeutic regimen. Group A consisted of 28 patients treated with RLX plus ALF, while Group B consisted of 32 patients with RLX alone. Among them, 20 in group A and 22 in group B completed this study. Contrary to our expectations, at either 6 months or 12 months after the initiation of treatment, RLX plus ALF did not increase BMD at any of the skeletal sites measured, including lumbar spine, femur, and radius, nor did it reduce bone-specific alkaline phosphatase or N-terminal telopeptide of type I collagen more than RLX alone. Our results do not support the hypothesis that the combination therapy of RLX and ALF exerts more beneficial effects on bone compared than with RLX alone. However, it still remains unclear from this study whether the combination therapy of RLX and ALF is more efficacious in preventing fractures compared with RLX alone. Further studies are needed to clarify these issues.