[Combination therapy for osteoporosis].

Combination therapy of the two agents for osteoporosis has not been determined to be more effective or not than the use of either one alone. Bisphosphonates are now the most widely used drugs for osteoporosis. Concurrent administration of bisphosphonate and vitamin D could increase bone mineral density (BMD) more than the use of bisphosphonate alone especially in the patients with vitamin D deficiency. Bisphosphonates increased BMD, but the increment of BMD was reached to plateau after two or three years. After stopping bisphosphonates, PTH administration was effective to gain more BMD. Sequential administration of antiresorber (bisphosphonate or raloxifene) and PTH could be more effective than the use of bisphosphonate alone. But there would be some differential effects of sequential treatment on BMD among antiresorbers. Longer-term studies of fractures are needed to determine whether and how antiresorptive drugs can be optimally used in conjunction with parathyroid hormone therapy. Further studies are necessary to fully ascertain the clinical significance of combination therapy in postmenopausal osteoporosis.