Treatment options for postmenopausal osteoporosis

Abstract

Osteoporosis is a systemic skeletal disease, characterized by a decrease of bone mass and bone quality, with a subsequent reduction of bone strenght and an increased risk of fracture. Hormone Therapy for menopausal women can significantly prevent osteopenia and osteoporosis, thus reducing the fracture risk. The use of HT, according to guidelines, is for postmenopausal women within 10 years since last menstruation or under the age of 60 years. Only HT at standard dose is able to reduce the fracture risk, while low-dose HT can prevent bone loss. Estrogens (with and without the addition of a progestin) and tibolone showed a fracture risk reduction effect. Also Tissue Selective Estrogen Complex (TSEC) can reduce the bone loss in postmenopause. For women without climacteric symptoms (as hot flushes and/or night sweats) the use of Selective Estrogen Receptor Modulators (SERMs) can be indicated, with a reduction of risk of vertebral fracture (for raloxifene and bazedoxifene), and non-vertebral fracture in high-risk women (for bazedoxifene). In more advence ages, antiresoptive agents as Bisphosphonates (Alendronate, Risedronate, Ibandronate and Zoledronate) can reduce the risk of vertebral, non-vertebral and hip fracture risk. Denosumab (DMAB), monoclonal antibobody against Rank-ligand (RANKL), providing an increased bone mass, significantly decreases risk of vertebral, non-vertebral and hip fracture. A drug holiday or treatment interruption is not recommended with DMAB, and DMAB dosing should not stopped without subsequent antiresorptive or other therapy to prevent a "rebound effect" with a possible increased risk of multiple vertebral fracture. Teriparatide (fraction 1-34 of recombinant PTH, administered daily 20 mcg sc) can stimulate osteoblast activity, with an important increase of bone mass and a significant reduction of risk of vertebral fracture, and of multiple vertebral fractures, but also of non-vertebral fragility fracture. Romosozumab (RMZ, adimnistered monlty 210 mg sc), is a bone-forming monoclonal antibody that binds to and inhibits sclerostin, with a dual effect of increasing bone formation and decreasing bone resorption. RMZ has showed to give marked increases in spine and hip bone density after 1 year of administration, also reducing fracture risk. The differences among the various treatments is the basis for the individualization of osteoporosis treatment, according to combination and/or sequential regimens of administration.