Effectiveness of monotherapy and combined therapy with calcitonin and minodronic acid hydrate, a bisphosphonate, for early treatment in patients with new vertebral fractures: An open-label, randomized, parallel-group study

Evidence related to the effectiveness of combination drug therapy for the treatment of osteoporosis is currently considered insufficient. Therefore, this study was performed to clarify the effects of monotherapy, and combination therapy, with a bisphosphonate (minodronic acid hydrate), a bone resorption inhibitor, and calcitonin (elcatonin), which is effective for the alleviation of pain due to vertebral fractures in osteoporotic patients.Study participants comprised of 51 female subjects with post-menopausal osteoporosis, whose main complaint was acute lower back pain caused by vertebral fractures. Subjects were randomly allocated into three groups and then administered with either intramuscular injections of elcatonin at a dose of 20 units weekly, minodronic acid hydrate at a dose of 1 mg daily, or a combination of these two drugs. As primary endpoints, time-dependent changes in levels of pain were assessed using a visual analog scale from baseline to 6 months of duration. In addition, we examined the effects of monotherapies, and a combination therapy on bone resorption, with changes in bone mineral density at 4 sites and advanced hip assessment parameters from baseline to 6 months. A two-tailed significance level of 5% was used for hypothesis testing.Elcatonin monotherapy showed some alleviation of pain immediately after any vertebral fractures, which was more than in the minodronic acid hydrate monotherapy group. In addition, the minodronic acid hydrate monotherapy group experienced more effective inhibited bone resorption than the elcatonin monotherapy group. In the combination therapy, the efficacy for alleviating pain and inhibiting bone resorption was equivalent to the effect observed in the elcatonin and minodronic acid hydrate monotherapy groups respectively, with further improved values of bone mineral density observed in the femoral neck and lumbar vertebrae, and in parameters of advanced hip assessment compared with both monotherapy groups.Combination therapy with elcatonin and minodronic acid hydrate appears to be an effective treatment for osteoporosis patients with lower back pain, caused by fresh vertebral fractures.