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Strontium ranelate, a strontium(II) salt of ranelic acid, is a medication for osteoporosis marketed as Protelos or Protos by Servier. Studies indicate it can also slow the course of osteoarthritis of the knee. The drug is unusual in that it both increases deposition of new bone by osteoblasts and reduces the resorption of bone by osteoclasts. It is therefore promoted as a "dual action bone agent" (DABA). On 13 May 2013, Servier released a Direct Healthcare Professional Communication which stated that important new restrictions for the use of Protelos are now in place, as randomised trials have shown an increased risk of myocardial infarction. Servier states that the use of Protelos is now restricted to treatment of severe osteoporosis in postmenopausal women at high risk for fracture.〔http://www.imb.ie/EN/Publications/Publications/Protelos-strontium-ranelate-Important-Safety-Information-from-Servier-as-approved-by-the-Irish-Medicines-Board.aspx〕 Also European Pharmacovigilance Risk Assessment Committee (PRAC) recommends restriction in the use of strontium ranelate, based on a routine benefit-risk assessment of the medicine, which included data showing an increased risk of heart problems, including heart attacks.〔http://www.ema.europa.eu/docs/en_GB/document_library/Medicine_QA/human/000560/WC500142021.pdf〕 On 21 February 2014 the European Medicine Agency recommended that Strontium Ranelate (Protelos) remain available with restrictions relative to patients with existing heart disease〔http://www.ema.europa.eu/ema/index.jsp?curl=pages/news_and_events/news/2014/02/news_detail_002031.jsp&mid=WC0b01ac058004d5c1〕 == Mode of action == Strontium, which has the atomic symbol Sr and the atomic number 38, belongs to the group II in the periodic table of the elements, just beneath calcium. Because its nucleus is very nearly the same size as that of calcium, the body easily takes up strontium and incorporates it into bones and tooth enamel in the place of calcium. This is not a health problem and in fact, it can provide a health benefit. For example, in clinical trials, the drug strontium ranelate was found to aid bone growth, increase bone density, and lessen vertebral, peripheral, and hip fractures in women. Strontium ranelate is an antiosteoporotic agent which both increases bone formation and reduces bone resorption, resulting in a rebalance of bone turnover in favor of bone formation. This is similar to the effects of choline stabilized orthosilicic acid. Strontium ranelate stimulates the calcium sensing receptors and leads to the differentiation of pre-osteoblast to osteoblast which increases the bone formation. Strontium ranelate also stimulates osteoblasts to secrete osteoprotegerin in inhibiting osteoclasts formed from pre-osteoclasts in relation to the RANKL system, which leads to the decrease of bone resorption. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Strontium ranelate」の詳細全文を読む スポンサード リンク
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