teriparatide + alfacalcidol

**Teriparatide + alfacalcidol** is a combination therapy of two drugs used primarily for the treatment of osteoporosis. Teriparatide is a recombinant form of human parathyroid hormone (PTH 1-34) and acts as an **anabolic (bone-building) agent** for osteoporosis by stimulating osteoblast activity and promoting bone formation, primarily through repeated activation of the parathyroid hormone type 1 receptor. Alfacalcidol is a **vitamin D analog (prodrug of calcitriol)** that increases serum calcium by promoting intestinal absorption of calcium, increasing renal reabsorption, and stimulating bone resorption when necessary. Combination therapy is sometimes considered for patients at high risk of fracture or with poor bone metabolism, and has been studied for safety, showing no unexpected or increased risk of hypercalcemia or hypercalciuria compared to monotherapy. Both drugs act synergistically to improve bone strength and mineralization in populations such as postmenopausal women with osteoporosis[1][2][5].