Strontium ranelate--a novel therapy for osteoporosis or a permutation of the same?

Osteoporosis was originally described in literature and art hundreds of years ago. Our ability to treat this disease lay dormant for centuries, but in the past 10 years, clinical trials have improved treatment options and efficacy. In this issue of the Journal , Meunier et al. 1 report on their study of the safety and effectiveness of strontium ranelate as a putative, novel therapy for osteoporosis. Strontium was originally detected in lead mines near Strontian, Scotland, in the late 1700s. This earth element is present in water and food and in trace amounts throughout the skeleton. Although absorption is poor when strontium is consumed orally, calcified tissues and areas of active osteogenesis take up 50 to 80 percent of the absorbed dose; excretion is largely renal. The uptake of strontium by bone seems to occur mostly by ionic substitution at low rates at the crystal surfaces of the bone matrix, without affecting mineral structure. 2 Because of its bone-seeking properties, strontium was used widely in the 1950s for the management of osteoporosis, 3 and more recently, the beta emitter strontium-89 was used for painful, malignant bone diseases. Strontium fell out of favor as a treatment for osteoporosis decades ago because mineralization defects were observed and the synthesis of calcitriol was inhibited. 3 These adverse effects were thought possibly to have been due to calcium-deficient diets and the doses used, and there has recently been renewed interest in developing this old element as a new compound, strontium ranelate. 4